Glossary

Find definitions for thousands of medical terms, treatments, and tests -- even health-related abbreviations, prefixes, and suffixes.

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Calcium is a mineral the body needs to make bones and teeth, transmit nerve messages, tighten (contract) muscles, and help the blood to clot and the heart to function properly. Calcium is found in milk and milk products (including yogurt and cheese); in certain leafy, green vegetables (broccoli, spinach, kale); in legumes; and in some nuts.

A person needs to eat 3 to 4 servings a day of foods high in calcium to get the recommended daily amount.

Last Revised: January 25, 2013

Author: Healthwise Staff

Medical Review: Kathleen Romito, MD - Family Medicine & Rhonda O'Brien, MS, RD, CDE - Certified Diabetes Educator

Calcium channel blocker medicines prevent calcium from entering muscle cells and blood vessels. As a result, blood vessels relax, which slows the heart rate and increases blood flow to the heart muscle while reducing blood pressure.

Calcium channel blockers are used to treat heart conditions, including high blood pressure, angina caused by coronary artery disease, and fast or irregular heart rhythms. They are also used to treat severe headaches.

Last Revised: April 4, 2011

Author: Healthwise Staff

Medical Review: E. Gregory Thompson, MD - Internal Medicine & Robert A. Kloner, MD, PhD - Cardiology

Carbohydrate is an essential nutrient that is an excellent source of energy (measured as calories) for the body and is the preferred fuel for the brain and nervous system. All forms of carbohydrate increase a person's blood sugar level, depending on the amount of carbohydrate in the food.

Carbohydrate comes in two forms: starch and sugar.

  • Starch (complex carbohydrate) is found in foods such as breads, cereals, grains, pasta, rice, flour, legumes, and vegetables. Foods high in starch provide longer-lasting energy than simple carbohydrates.
  • Sugar (simple carbohydrate) is found in foods such as fruits, juices, milk, honey, desserts, and candy. Foods high in simple sugar provide quick energy.

Last Revised: January 25, 2013

Author: Healthwise Staff

Medical Review: Kathleen Romito, MD - Family Medicine & Rhonda O'Brien, MS, RD, CDE - Certified Diabetes Educator

Carcinoid syndrome is a rare and malignant disease that attacks the small intestine, stomach, and pancreas. Symptoms include flushing, diarrhea, and wheezing.

In carcinoid syndrome, slow-growing tumors can spread (metastasize) to the liver, lungs, and ovaries. In later stages, this disease may result in heart failure.

Last Revised: July 24, 2012

Author: Healthwise Staff

Medical Review: Rakesh K. Pai, MD, FACC - Cardiology, Electrophysiology & Robert A. Kloner, MD, PhD - Cardiology

Cardiac catheterization with coronary angiogram is a test to check the heart and coronary arteries. It is used to check blood flow in the coronary arteries, check blood flow and blood pressure in the chambers of the heart, find out how well the heart valves work, and check for problems in how the wall of the heart moves.

The purpose of cardiac catheterization and angiogram is to find out if a person has disease in the coronary arteries (atherosclerosis). If the person has atherosclerosis, this test can pinpoint the size and location of fat and calcium deposits (plaque) that are narrowing the coronary arteries. Results from cardiac catheterization and angiogram help show whether treatment with bypass surgery or percutaneous coronary intervention (PCI), such as angioplasty, may be effective.

During cardiac catheterization, a soft, thin tube (catheter) is put in a blood vessel in the arm or groin and gently moved into the heart. A special dye (contrast material) that shows up on X-rays is injected through the catheter. An X-ray picture on a computer screen shows the dye moving through the blood vessels and into the chambers of the heart. X-ray pictures of the dye can check for narrowing or blockage of the arteries.

Last Revised: July 20, 2011

Author: Healthwise Staff

Medical Review: Rakesh K. Pai, MD, FACC - Cardiology, Electrophysiology & George Philippides, MD - Cardiology

Cardiac electrophysiologists are cardiology doctors (cardiologists) who have specialized training in the heart's electrical system. They specialize in diagnosing and treating heart rhythm problems (arrhythmias) such as atrial fibrillation.

Cardiac electrophysiologists can be board-certified through the Board of Internal Medicine, which is recognized by the American Board of Medical Specialties.

Last Revised: August 17, 2012

Author: Healthwise Staff

Medical Review: Anne C. Poinier, MD - Internal Medicine & E. Gregory Thompson, MD - Internal Medicine

Cardiac rehabilitation (rehab) is a supervised program that uses exercise, education, and support to help people recover from a heart attack, heart surgery, or other heart problems. Cardiac rehab programs are medically supervised and individually designed based on a person's needs and overall health.

A rehab program helps people:

  • Reduce the risk of dying of heart disease.
  • Reduce cardiac risk factors, such as increased weight, high blood pressure, high cholesterol, and smoking.
  • Control symptoms of heart disease.
  • Be more active.
  • Improve their quality of life.
  • Return to their usual activities, including work.

Last Revised: September 27, 2012

Author: Healthwise Staff

Medical Review: Rakesh K. Pai, MD, FACC - Cardiology, Electrophysiology & John A. McPherson, MD, FACC, FSCAI - Cardiology

Cardiac tamponade is a condition caused by too much fluid in the space between the heart and the sac that surrounds it, called the pericardium. This fluid collection can put weight and pressure on the heart, which means that it cannot expand properly and so it does not fill with normal amounts of blood.

Cardiac tamponade is an emergency condition. The inability of the heart to pump enough blood may eventually lead to heart failure.

Last Revised: April 5, 2011

Author: Healthwise Staff

Medical Review: E. Gregory Thompson, MD - Internal Medicine & Stephen Fort, MD, MRCP, FRCPC - Interventional Cardiology

Cardiogenic shock is a condition caused when the blood flow in the body suddenly and severely decreases. Blood flow becomes so low that adequate blood is not able to return to the heart so that it can function normally.

When oxygen cannot be delivered to organs and tissue, symptoms that may develop include pale or bluish skin; weak but rapid pulse; shallow, fast breathing; extreme thirst; and possibly fainting (syncope).

Last Revised: April 26, 2012

Author: Healthwise Staff

Medical Review: Rakesh K. Pai, MD, FACC - Cardiology, Electrophysiology & Stephen Fort, MD, MRCP, FRCPC - Interventional Cardiology

Cardiologists are medical doctors who specialize in the diagnosis and treatment of diseases or conditions of the heart and blood vessels, such as chest pain (angina), irregular heart rhythms, high blood pressure, heart failure, or heart attacks.

Cardiologists administer tests that show how well a person's heart is working, such as a treadmill test (exercise electrocardiogram). And they perform certain treatment procedures. They can further specialize in interventional cardiology (the use of mechanical treatment methods, such as angioplasty) or electrophysiology (treatments involving the heart's electrical system). Also, they may specialize in treating specific age groups, such as a pediatric cardiologist, who only treats children.

Cardiologists can be board-certified through the Board of Internal Medicine, which is recognized by the American Board of Medical Specialties. Pediatric cardiologists are recognized by the American Academy of Pediatrics.

Last Revised: August 17, 2012

Author: Healthwise Staff

Medical Review: Anne C. Poinier, MD - Internal Medicine & E. Gregory Thompson, MD - Internal Medicine

Cardiovascular surgeons are medical doctors who specialize in surgery of the heart and blood vessels. They typically perform heart surgeries and treat people who have a blockage in the blood vessels leading to the heart (coronary artery disease) or problems with heart valves. They may also do certain thoracic (chest and lung) surgeries.

Cardiovascular surgeons may further specialize in treating people of specific age groups, such as pediatric cardiovascular surgeons, who only treat children and often treat heart problems related to birth defects.

Cardiovascular surgeons can be board-certified by the Board of Surgery in general surgery or vascular surgery. The Board of Surgery is recognized by the American Board of Medical Specialties.

Last Revised: August 17, 2012

Author: Healthwise Staff

Medical Review: Anne C. Poinier, MD - Internal Medicine & E. Gregory Thompson, MD - Internal Medicine

The carotid artery travels up each side of the neck and branches into smaller vessels that supply blood to the brain. Blood flowing through the carotid arteries (carotid pulses) can be felt on each side of the neck next to the windpipe (trachea).

The carotid arteries are a common location for hardening of the artery wall (atherosclerosis) to occur.

Last Revised: January 3, 2013

Author: Healthwise Staff

Medical Review: E. Gregory Thompson, MD - Internal Medicine & Karin M. Lindholm, DO - Neurology

Cartilage is a type of firm, thick, slippery tissue that coats the ends of bones where they meet with other bones to form a joint. Cartilage lines the joint space between bones throughout the body, and it acts as a protective cushion between bones to absorb the stress applied to joints during movement.

Cartilage is made up of protein strands called collagen that form a tough, meshlike framework. The mesh is filled with substances that hold water, much like a sponge. When weight is placed on cartilage, water is squeezed out of the mesh. When weight is taken off, the water returns. Cartilage does not contain blood vessels or nerves. Although cartilage is very strong, it can be damaged when a joint is injured.

Last Revised: June 5, 2012

Author: Healthwise Staff

Medical Review: Anne C. Poinier, MD - Internal Medicine & Nancy Ann Shadick, MD, MPH - Internal Medicine, Rheumatology

A cataract is a painless, cloudy area in the lens of your eye. A cataract blocks light from reaching the retina (the nerve layer at the back of the eye) and may cause vision problems.

Cataracts are common in older adults and are linked to aging. Smoking and exposure to too much sunlight are other risk factors. Cataracts can also happen after an eye injury, as a result of eye disease, after you use certain medicines, or as a result of health problems such as diabetes.

Sometimes children are born with cataracts.

Surgery is used to remove cataracts that are causing a problem.

Last Revised: September 26, 2012

Author: Healthwise Staff

Medical Review: Adam Husney, MD - Family Medicine

Catecholamines are hormones made chiefly by the adrenal glands, located above the kidneys. The main catecholamines are adrenaline (epinephrine), noradrenaline (norepinephrine), and dopamine.

Catecholamines increase heart rate, blood pressure, breathing rate, muscle strength, and mental alertness. They also reduce the amount of blood going to the skin and increase blood flow to the major organs, such as the brain, heart, and kidneys. Catecholamines are often released into the bloodstream in response to stress or fright and prepare the body for "fight-or-flight."

Inotropic medicines, such as dobutamine, mimic the action of catecholamines in the heart and can help strengthen the heartbeat.

Last Revised: June 20, 2012

Author: Healthwise Staff

Medical Review: E. Gregory Thompson, MD - Internal Medicine & Alan C. Dalkin, MD - Endocrinology

Catheter ablation is a procedure that treats heart rhythm problems by destroying tiny areas of heart tissue that are causing the problems. Guided by X-rays, the doctor inserts thin tubes called catheters into a blood vessel, typically in the groin or neck, and feeds them into the heart.

Wires in the catheters help the doctor identify the type of rhythm problem and find the problem areas. Then the doctor uses the wires to send energy—heat or freezing cold—to those areas. The energy destroys, or ablates, the tissue. After it's destroyed, the tissue can no longer cause a problem. The areas of tissue are very tiny. And destroying them does not affect the heart's ability to do its job.

Last Revised: December 14, 2012

Author: Healthwise Staff

Medical Review: Rakesh K. Pai, MD, FACC - Cardiology, Electrophysiology & John M. Miller, MD, FACC - Cardiology, Electrophysiology

Cellulitis is a skin infection, usually caused by Streptococcus or Staphylococcus bacteria. Cellulitis usually develops after a break in the skin from a scrape, cut, bite, or puncture, or after a rash.

A doctor should evaluate symptoms that can occur with cellulitis, which may include:

  • Painful, red, hot, swollen skin that may crack, split, or weep fluid.
  • Red streaks extending from the red area toward the body (lymphangitis).
  • Fever and chills.
  • Drainage of pus.
  • Swollen glands.
  • General feeling of illness (malaise).

Facial cellulitis in children requires immediate medical attention to prevent potentially dangerous eye or brain infection. Cellulitis usually is treated with antibiotics, rest and elevation of the affected area, and warm compresses. Cellulitis may be more severe and require a hospital stay for people who have decreased blood flow (venous stasis), long-term swelling, diabetes, or an impaired immune system.

Last Revised: February 14, 2011

Author: Healthwise Staff

Medical Review: Kathleen Romito, MD - Family Medicine & Alexander H. Murray, MD, FRCPC - Dermatology

The central nervous system (CNS) is made up of the brain and the spinal cord. The central nervous system controls thought processes, guides movement, and registers sensations throughout the body.

The spinal cord is a single continuous structure that goes from the brain through the base of the skull and down the spinal column. Individual paired spinal nerves continue down to the tailbone.

Injuries or diseases that affect the central nervous system can sometimes cause permanent loss of function and disability.

Last Revised: September 1, 2011

Author: Healthwise Staff

Medical Review: William H. Blahd, Jr., MD, FACEP - Emergency Medicine & H. Michael O'Connor, MD - Emergency Medicine

Cerebral palsy (CP) is a group of motor problems and physical disorders that result from a brain injury or abnormal brain development and that may occur during fetal growth, at the time of birth, or in the first 2 or 3 years of a child's life. The brain injury that causes CP does not get worse over time, but symptoms may start, change, or become more severe as a child grows.

Cerebral palsy affects the muscles of a part or side of the body or sometimes the entire body. Uncontrolled reflex movements and muscle tightness (spasticity) occur with varying severity. Physical problems of cerebral palsy range from mild (a clumsy walk) to severe (an inability to control movement of the arms, legs, or muscles of the mouth and tongue). People with severe forms of cerebral palsy are more likely to have other problems, such as seizures or intellectual disability.

Sometimes the exact cause of cerebral palsy is known, such as when brain damage follows a serious infection or head injury. In many cases the exact cause of cerebral palsy is not known.

Cerebral palsy cannot be cured. But a comprehensive treatment program can help people with CP maximize their abilities and physical strength, prevent complications, and improve their quality of life. Treatment usually includes physical therapy and speech therapy. Medicines, surgery, special devices and equipment, and other individualized treatments also may be used.

Last Revised: September 20, 2012

Author: Healthwise Staff

Medical Review: Susan C. Kim, MD - Pediatrics & Louis Pellegrino, MD - Developmental Pediatrics

Diabetes educators are health professionals, such as doctors, nurses, dietitians, pharmacists, exercise specialists, and social workers, who specialize in the treatment of people who have diabetes.

Diabetes educators teach about nutrition, exercise, medicine, blood sugar monitoring, and emotional adjustment to diabetes. They work in a variety of settings, such as hospitals, doctor's offices, nursing homes, and neighborhood clinics. They may teach people in groups or individually.

Certified diabetes educators (CDEs) are licensed in their professional fields in the states in which they practice. Most are certified by the National Certification Board of Diabetes Educators. Certification is voluntary.

Last Revised: August 17, 2012

Author: Healthwise Staff

Medical Review: Anne C. Poinier, MD - Internal Medicine & E. Gregory Thompson, MD - Internal Medicine

Chemotherapy is the use of medicine to destroy cancer cells.

Sometimes medicines are put into the blood, usually in a vein, so that they can travel to cells all over the body. This is called systemic chemotherapy.

But chemotherapy also may be:

  • Taken by mouth (orally), in pills, capsules, or a liquid.
  • Mixed into a cream that is rubbed onto the skin (topically).
  • Given as a shot (injection) into a muscle or under the skin.
  • Given through a thin tube (a catheter) directly into the abdominal cavity (intraperitoneal chemotherapy).
  • Given through a catheter directly into an organ, such as the bladder (intravesical chemotherapy).

Chemotherapy can cause side effects, such as nausea and vomiting. Some side effects go away after treatment is finished. But other side effects, such as infertility, may be permanent.

Last Revised: May 2, 2011

Author: Healthwise Staff

Medical Review: E. Gregory Thompson, MD - Internal Medicine & Christopher G. Wood, MD, FACS - Urology, Oncology

Cholesterol is an important type of fat (lipid) that is made by the body. It is needed for the body to function. It also is found in foods that are made from animal products (meat and dairy products).

Cells need cholesterol to function. But excess cholesterol in the blood builds up in blood vessels and may lead to hardening of the arteries (atherosclerosis), heart disease, and stroke. People who have diabetes are at higher risk for atherosclerosis.

There are two main forms of cholesterol:

  • Low-density lipoprotein (LDL) is called "bad cholesterol." Most efforts to lower cholesterol are aimed at reducing levels of LDL.
  • High-density lipoprotein (HDL) is called "good cholesterol." It can help remove excess cholesterol from the blood vessels.

A person's cholesterol level can be checked with a blood test.

Last Revised: June 29, 2012

Author: Healthwise Staff

Medical Review: Kathleen Romito, MD - Family Medicine & Robert A. Kloner, MD, PhD - Cardiology & Rakesh K. Pai, MD, FACC - Cardiology, Electrophysiology

Chronic bronchitis is an inflammation in the airways leading to and within the lungs (bronchial tubes). The inflammation may narrow these tubes, which makes it hard to breathe.

Chronic bronchitis causes a persistent cough that brings up mucus (sputum). Chronic bronchitis is a form of chronic obstructive pulmonary disease (COPD).

Last Revised: July 10, 2012

Author: Healthwise Staff

Medical Review: E. Gregory Thompson, MD - Internal Medicine & Robert L. Cowie, MB, FCP(SA), MD, MSc, MFOM - Pulmonology

Chronic female pelvic pain is pain in a woman's lower abdomen that lasts for 6 months or more. It may be constant or come and go and range from mild to severe.

Many things can cause chronic pelvic pain, including pelvic infections. But sometimes the cause is a mystery.

Last Revised: October 30, 2012

Author: Healthwise Staff

Medical Review: Sarah Marshall, MD - Family Medicine & Kirtly Jones, MD - Obstetrics and Gynecology

Chronic kidney disease happens when your kidneys no longer filter your blood the way they should, so wastes build up in your blood. This has probably been going on for years, and it may keep getting worse over time. If your disease gets worse, you could have kidney failure.

Diabetes and high blood pressure cause most chronic kidney disease. Controlling those diseases can help slow or stop the damage to your kidneys.

Last Revised: September 27, 2012

Author: Healthwise Staff

Medical Review: Anne C. Poinier, MD - Internal Medicine & Mitchell H. Rosner, MD - Nephrology

Chronic obstructive pulmonary disease (COPD) is a lung disease that makes it hard to breathe. It's often a mix of two diseases caused by smoking: chronic bronchitis and emphysema. Over time, it can lead to severe shortness of breath and heart problems.

COPD can't be cured, but medicines and lifestyle changes may help reduce symptoms.

The only reliable way to slow COPD is to stop smoking.

Last Revised: September 27, 2012

Author: Healthwise Staff

Medical Review: E. Gregory Thompson, MD - Internal Medicine & Ken Y. Yoneda, MD - Pulmonology

Pain is called chronic if it lasts for 3 months or longer. It's normal to have pain when you are injured or ill. But pain that lasts for weeks, months, or years isn't normal.

There are many treatment options for chronic pain. They include exercise, behavioral therapy, physical therapy, medicines, and complementary therapies such as acupuncture and massage.

Last Revised: January 9, 2013

Author: Healthwise Staff

Medical Review: Anne C. Poinier, MD - Internal Medicine & Nancy Greenwald, MD - Physical Medicine and Rehabilitation

Cirrhosis (say "suh-ROH-sus") is a very serious condition in which healthy tissue in the liver is replaced with scar tissue. The scarring keeps the liver from working as it should. For example, the liver may stop making clotting factors, which can lead to bleeding problems. Bile and poisons may build up in the blood. The scarring can also cause high blood pressure in the vein that carries blood to the liver.

Last Revised: October 9, 2012

Author: Healthwise Staff

Medical Review: Adam Husney, MD - Family Medicine & W. Thomas London, MD - Hepatology

Clotting factors are substances in the blood that help stop bleeding when a blood vessel is damaged. People who have clotting disorders, such as hemophilia, have clotting factors that do not function properly.

When the blood doesn't clot normally, even minor injuries can cause serious bleeding. This can lead to blood loss, injury to internal organs, or permanent damage to muscles or joints.

Most people who have clotting disorders can successfully manage their bleeding problems with clotting factor replacement therapy. Clotting factors may be injected on a regular basis to prevent bleeding episodes, or on an as-needed basis to prevent or control a bleeding episode that has occurred or is likely to occur.

Last Revised: August 3, 2011

Author: Healthwise Staff

Medical Review: E. Gregory Thompson, MD - Internal Medicine & Brian Leber, MDCM, FRCPC - Hematology

Clubbing is a condition in which the ends of the fingers and toes swell and the nails bulge outward. The nails wrap around the fingers or toes and look raised, curved, and shiny.

Clubbing occurs more frequently in children born with heart defects and people with chronic heart, lung, liver, or thyroid disease. But simple hereditary clubbing can occur without heart or lung problems.

Last Revised: October 11, 2011

Author: Healthwise Staff

Medical Review: John Pope, MD - Pediatrics & Larry A. Latson, MD - Pediatric Cardiology

Coarctation of the aorta is a common heart defect present at birth.

With this defect, a portion of the large blood vessel that carries blood from the heart to the rest of the body (aorta) is abnormally narrowed or pinched. Coarctation of the aorta makes it harder for the heart to pump blood to the body. Over time, this can lead to high blood pressure, heart failure, or other complications.

The most obvious symptoms of coarctation of the aorta are signs of heart failure—such as difficulty breathing, poor weight gain, sweating, and being sleepy and fussy most of the time—and decreased pulses in the legs. This condition is usually detected in newborns during normal blood pressure checks and by listening to the heart. Further tests, such as echocardiography, may be done to confirm the diagnosis.

Coarctation of the aorta requires repair by surgery or heart catheterization. If the condition is not repaired, a person with coarctation of the aorta may not live past the age of 40 or 50.

Last Revised: October 11, 2011

Author: Healthwise Staff

Medical Review: John Pope, MD - Pediatrics & Larry A. Latson, MD - Pediatric Cardiology

Cognitive impairment occurs when there is a problem with perceiving, thinking, or remembering. Strokes are a common cause of cognitive impairment. Other causes include head injuries and some chronic diseases, such as sickle cell disease or multiple sclerosis.

Cognitive impairment may cause difficulties with:

  • Memory, especially short-term memory.
  • Problem solving.
  • Attention span, especially in a mental task such as a math calculation.
  • Expressing oneself, such as finding the right words to use in a conversation.

Therapy may help a person make the most of his or her abilities.

Last Revised: September 20, 2012

Author: Healthwise Staff

Medical Review: Susan C. Kim, MD - Pediatrics & Louis Pellegrino, MD - Developmental Pediatrics

Cognitive-behavioral therapy is a type of counseling that focuses on changing certain thoughts and behavior patterns to control the symptoms of a condition. It's used to treat a variety of problems, such as stress, depression, anxiety and panic disorders, eating disorders, ongoing (chronic) pain, and chronic fatigue syndrome.

Last Revised: January 11, 2013

Author: Healthwise Staff

Medical Review: Kathleen Romito, MD - Family Medicine & Lisa S. Weinstock, MD - Psychiatry

Colonoscopy is the inspection of the entire large intestine (colon) using a long, flexible, lighted viewing scope (colonoscope), which is usually linked to a video monitor similar to a TV screen. A colonoscopy may be done to screen for cancer or to investigate symptoms, such as bleeding.

Colonoscopy is done in the hospital or a doctor's office that has the necessary equipment. Preparation for the test includes emptying the bowels ahead of time using a laxative or enema. The person undergoing colonoscopy is given medicine to relieve pain and to make him or her drowsy. The test usually takes 30 to 45 minutes, but it may take longer, depending upon what is found and what is done during the test.

A doctor will collect a tissue sample (biopsy) from any abnormal area. The tissue is then analyzed by a pathologist.

Last Revised: December 7, 2011

Author: Healthwise Staff

Medical Review: Adam Husney, MD - Family Medicine & Arvydas D. Vanagunas, MD - Gastroenterology

Colorectal cancer happens when cells in your colon or rectum grow abnormally and out of control. It may start as a polyp, or small growth, in your colon or rectum. The cancer cells can spread to other parts of your body.

This cancer is also called colon cancer or rectal cancer, depending on where the cancer is. It is most common in people older than 50.

Treatment works best when the cancer is found early. Screening tests can help find polyps and can find cancer that is still in its early stages and hasn't spread yet.

Last Revised: September 26, 2012

Author: Healthwise Staff

Medical Review: Adam Husney, MD - Family Medicine

A complete blood count (CBC) is a blood test that gives important information about the kinds and numbers of cells in the blood, especially red blood cells, white blood cells, and platelets. A CBC helps your doctor evaluate symptoms (such as weakness, fatigue, or bruising) and diagnose conditions (such as anemia, infection, and many other disorders).

A CBC may be done to check for low red blood cells (anemia), problems with white blood cells, find an infection, find diseases of the blood, such as leukemia, or check to see if medicine or radiation treatment is working.

Last Revised: August 6, 2012

Author: Healthwise Staff

Medical Review: E. Gregory Thompson, MD - Internal Medicine & Joseph O'Donnell, MD - Hematology, Oncology

Congenital heart defects are structural heart problems or abnormalities that have been present since birth.

Congenital heart defects usually have no known cause. In some cases, they may be passed from a parent to a child (inherited). They also may occur in the developing baby (fetus) of a woman who has an infection or who is exposed to radiation or other toxic substances during her pregnancy.

Having a congenital heart defect increases the risk for complications, such as heart failure, endocarditis, atrial fibrillation, and heart valve problems.

Most congenital heart defects are detected shortly after birth, although some are not discovered for years. Some defects are severe enough to cause death. Some resolve on their own and may not need any treatment. Babies with large or complex defects usually require surgery. Many children with corrected heart defects go on to lead normal lives. But they usually require lifelong monitoring of their condition.

Last Revised: October 11, 2011

Author: Healthwise Staff

Medical Review: John Pope, MD - Pediatrics & Larry A. Latson, MD - Pediatric Cardiology

Constrictive pericarditis is stiffening and thickening of the membrane sac around the heart (pericardium). Repeated or prolonged episodes of inflammation of the pericardium (pericarditis) can lead to constrictive pericarditis, which restricts the heart's ability to pump effectively.

Constrictive pericarditis can be caused by medical conditions or treatments that involve inflammation. These include radiation therapy and complications after surgery. But the cause is often unknown.

If the pericardium becomes thick and stiff and interferes with the heart's ability to pump blood, it can be removed in a procedure called pericardiectomy. Although the pericardium surrounds and cushions the heart, the heart can function without it, if necessary.

Last Revised: April 5, 2011

Author: Healthwise Staff

Medical Review: E. Gregory Thompson, MD - Internal Medicine & Stephen Fort, MD, MRCP, FRCPC - Interventional Cardiology

A contracture is the abnormal shortening of muscle or other tissue. It may be caused by muscle spasm, wasting away of tissue and muscle (atrophy), scar formation from injury, chronic disease, or lack of use.

A contracture often develops in a joint affected by arthritis or in a paralyzed limb. It may make it impossible to move the joint normally. A contracture causes surrounding muscle, tendons, ligaments, and bone to shorten or bend. And it can lead to permanent deformity and disability.

Contractures are treated in many ways, including physical therapy, casts, and surgery.

Last Revised: June 5, 2012

Author: Healthwise Staff

Medical Review: Susan C. Kim, MD - Pediatrics & John Pope, MD - Pediatrics

Contrast material, or contrast dye, is a substance used to make specific organs, blood vessels, or types of tissue (such as tumors) more visible on X-rays. Contrast material may also be used during a CT scan, an ultrasound, or an MRI scan.

Common contrast material substances include iodine, barium, and gadolinium.

Last Revised: May 16, 2011

Author: Healthwise Staff

Medical Review: Kathleen Romito, MD - Family Medicine & Howard Schaff, MD - Diagnostic Radiology

Core stabilization (core stability or core strength) means using the muscles of the trunk to support the spine and body during activity. The trunk muscles include those in the abdomen and back, around the neck and shoulder blades, and around the pelvis, hips, groin, and buttocks.

Core stabilization helps improve posture, balance, strength, and coordinated movement, and helps protect the body from injury.

Last Revised: March 4, 2011

Author: Healthwise Staff

Medical Review: Adam Husney, MD - Family Medicine & David A. Fleckenstein, MPT - Physical Therapy

Coronary arteries are vessels that provide oxygen-rich blood and other nutrients to the heart muscle. The two main coronary blood vessels, which branch from the body's main artery (aorta), are the right coronary artery (RCA) and the left coronary artery (LCA).

The coronary arteries attach to and wrap around the heart's surface. The left side of the heart is larger and more muscular because it pumps blood to the rest of the body. The left coronary artery branches off into smaller arteries:

  • Left anterior descending artery.
  • Left circumflex artery, which encircles the heart muscle.

The right side of the heart pumps blood to the lungs and related structures. The right marginal branch usually extends from the right coronary artery and supplies blood to the lower side of the heart.

Last Revised: April 6, 2012

Author: Healthwise Staff

Medical Review: Rakesh K. Pai, MD, FACC - Cardiology, Electrophysiology & Robert A. Kloner, MD, PhD - Cardiology

Coronary artery bypass graft surgery is done to go around a portion of an artery that has been narrowed or blocked by plaque buildup (atherosclerosis). It is a treatment for coronary artery disease.

The blocked portion of the artery is bypassed using a blood vessel taken from elsewhere in the body (usually the chest or leg). Blood is redirected through the new blood vessel, restoring blood flow to the affected portion of the heart muscle.

Last Revised: April 5, 2012

Author: Healthwise Staff

Medical Review: Rakesh K. Pai, MD, FACC - Cardiology, Electrophysiology & Robert A. Kloner, MD, PhD - Cardiology

Coronary artery disease happens when fatty deposits called plaque (say "plak") build up inside your coronary arteries. Those are the blood vessels that supply blood and oxygen to your heart. Plaque buildup reduces the amount of blood that gets to your heart. It can lead to chest pain or heart attack.

Coronary artery disease (also called CAD) is the most common type of heart disease. It's also the number one killer of both men and women in the United States.

Last Revised: October 9, 2012

Author: Healthwise Staff

Medical Review: Rakesh K. Pai, MD, FACC - Cardiology, Electrophysiology & Robert A. Kloner, MD, PhD - Cardiology

Corticosteroid medicines are similar to natural hormones produced in the body that help control many necessary functions, including blood sugar and salt (electrolyte) levels, the body's water balance, and immune system function. Corticosteroid medicines are often used to treat diseases that cause inflammation, such as lupus and rheumatoid arthritis.

Common prescription corticosteroids include dexamethasone, hydrocortisone, and prednisone.

Long-term use of corticosteroids has many side effects, including weight gain, stomach ulcers, sleeping difficulties, increased blood pressure, increased blood sugar (glucose), delayed wound healing, and a reduced ability to fight infection. Other problems associated with corticosteroid use include cataract formation, decreased blood flow to the hip joint that causes deterioration of the joint (aseptic necrosis or avascular necrosis), and osteoporosis.

Last Revised: May 10, 2012

Author: Healthwise Staff

Medical Review: Anne C. Poinier, MD - Internal Medicine & Nancy Ann Shadick, MD, MPH - Internal Medicine, Rheumatology

Cortisol is a hormone produced by the adrenal glands, which are located just above the kidneys. Cortisol affects almost every organ in the body and is important for body functions such as breaking down glycogen and fat for energy, managing stress, and maintaining blood pressure.

Cortisol levels increase when the pituitary gland in the brain releases another hormone called adrenocorticotropic hormone (ACTH). Cortisol levels also rise during times of stress.

Last Revised: June 20, 2012

Author: Healthwise Staff

Medical Review: E. Gregory Thompson, MD - Internal Medicine & Alan C. Dalkin, MD - Endocrinology

Counseling is professional guidance to help a person, family, or group of individuals recognize and deal with issues that are interfering with their mental well-being. Counseling involves regular meetings (sessions) with a qualified counselor, such as a psychiatrist, psychologist, licensed professional counselor, or clinical social worker.

Counseling, which may also be called psychotherapy or therapy, can be done on an individual, family, or group basis.

Last Revised: January 11, 2013

Author: Healthwise Staff

Medical Review: Kathleen Romito, MD - Family Medicine & Lisa S. Weinstock, MD - Psychiatry

CPR (cardiopulmonary resuscitation) is pushing down on a person's chest and breathing into his or her mouth. It is used in emergencies when a person's heart stops beating, or when he or she stops breathing.

CPR works to move blood to the person's brain to help prevent brain damage. CPR can help keep a person alive until a health professional arrives.

The steps of CPR are C-A-B:

  • C for compression
  • A for airway
  • B for breathing

Last Revised: March 27, 2012

Author: Healthwise Staff

Medical Review: William H. Blahd, Jr., MD, FACEP - Emergency Medicine & David Messenger, MD

Creatinine is a waste product formed by the breakdown of a substance (creatine) important for converting food into energy (metabolism). The creatinine is filtered out of the blood by the kidneys and then passed out of the body in urine.

If the kidneys are damaged and can't function normally, the amount of creatinine in the urine decreases while the amount of creatinine in the blood increases.

Last Revised: August 9, 2012

Author: Healthwise Staff

Medical Review: E. Gregory Thompson, MD - Internal Medicine & Michael Mallea, MD - Nephrology

A computed tomography angiogram (CT angiogram) is a test that uses X-rays to provide detailed pictures of the heart and the blood vessels that go to the heart, lung, brain, kidneys, head, neck, legs, and arms. The test uses a special dye that is put into a vein (IV) to make very detailed pictures of the blood vessels.

A CT angiogram can show whether a blood vessel is blocked, where the blockage is, and how big the blockage is. The test can also show whether there is a bulge (aneurysm) or a buildup of fatty material called plaque in a blood vessel.

Last Revised: June 13, 2012

Author: Healthwise Staff

Medical Review: Rakesh K. Pai, MD, FACC - Cardiology, Electrophysiology & George Philippides, MD - Cardiology

A computed tomography (CT) scan uses X-rays to make detailed pictures of structures inside of the body.

During the test, you will lie on a table that is attached to the CT scanner, which is a large doughnut-shaped machine. The CT scanner sends X-ray pulses through the body. Each pulse lasts less than a second and takes a picture of a thin slice of the organ or area being studied. One part of the scanning machine can tilt to take pictures from different positions. The pictures are saved on a computer.

A CT scan can be used to study any body organ, such as the liver, pancreas, intestines, kidneys, adrenal glands, lungs, and heart. It also can study blood vessels, bones, and the spinal cord.

An iodine dye (contrast material) is often used to make structures and organs easier to see on the CT pictures. The dye may be used to check blood flow, find tumors, and look for other problems. Dye can be put in a vein (IV) in your arm, or you may drink the dye for some tests. CT pictures may be taken before and after the dye is used.

Last Revised: June 13, 2011

Author: Healthwise Staff

Medical Review: Adam Husney, MD - Family Medicine & Howard Schaff, MD - Diagnostic Radiology

Cyanotic heart defects are abnormal openings between the heart chambers that allow oxygen-poor blood from the right side of the heart to mix with oxygen-rich blood from the left side of the heart. When a large amount of oxygen-poor blood mixes with oxygen-rich blood, it causes a bluish tint (cyanosis) in the skin, lips, and nail beds.

Last Revised: October 11, 2011

Author: Healthwise Staff

Medical Review: John Pope, MD - Pediatrics & Larry A. Latson, MD - Pediatric Cardiology

Cystic fibrosis is a chronic and progressive disease, usually diagnosed in childhood, that causes mucus to become thick and sticky. The mucus builds up and clogs passages in the lungs, pancreas, and many other organs in the body.

  • In the lungs, cystic fibrosis causes respiratory problems when thicker-than-normal mucus forms in the airways and lungs. Children who have cystic fibrosis almost always have breathing problems and frequent lung infections.
  • In the pancreas, the mucus blockage can interfere with normal digestive processes and increase the risk of infection. Babies and children who have cystic fibrosis may not be able to absorb nutrients from food and may have below-normal growth and development. Weight loss and difficulty gaining or maintaining weight are common problems for people of all ages who have cystic fibrosis.

Early symptoms of cystic fibrosis include abnormally salty sweat or skin and a failure to thrive, which includes a poor appetite, lack of energy, and weight loss during infancy. Some babies who have cystic fibrosis are born with a blocked small intestine. Later symptoms include coughing up mucus and a lack of energy. Adults who have cystic fibrosis may have fertility problems.

There is no cure for cystic fibrosis. Management of the disease varies from person to person and generally focuses on treating respiratory and digestive problems to prevent infection and other complications. Treatment usually involves a combination of medicines and home treatment methods, such as respiratory and nutritional therapies.

Last Revised: June 15, 2011

Author: Healthwise Staff

Medical Review: John Pope, MD - Pediatrics & Susanna McColley, MD - Pediatric Pulmonology