Catamenial epilepsy (CE), also known as menstrual seizures, is linked to a woman's menstrual cycle and related hormone levels in the body. Women with CE often have more seizures during certain times of their cycle.

A cataract is a clouding of the lens of the eye. This is an area that is normally clear. Cataracts can cause cloudy or blurry vision.

A cataract is a clouding over the lens of the eye. This area is normally clear (transparent). Some cataracts are small and don’t cause any trouble with vision. Others can cause visual problems in children. Cataracts are rare in children.

Catecholaminergic polymorphic ventricular tachycardia, or CPVT, is a rare genetic condition. It causes an irregular heart rhythm that can be life threatening. It often shows up in childhood. The first sign is often fainting or near ...

The cauda equina is the sack of nerve roots (nerves that leave the spinal cord between spaces in the bones of the spine to connect to other parts of the body) at the lower end of the spinal cord. These nerve roots provide the ability to ...

Brain and spinal cord cavernous malformations are an abnormal tangle of vein-like structures. Unlike arteriovenous malformations, these do not have a high blood flow traveling through them. (They are also known as cavernous angiomas, ...

Celiac disease is a digestive problem that hurts your small intestine. It stops your body from taking in nutrients from food. You may have celiac disease if you are sensitive to gluten.

Cellulitis is a serious deep infection of the skin caused by bacteria. It usually occurs in an area that has already had an injury or skin break.

Cellulitis is a spreading skin infection. It may affect the upper skin layer. Or it may affect the deeper skin and layer of fat under the skin. When cellulitis affects the upper skin layer, it may be called erysipelas. This type of ...

Cellulitis is a serious type of infection and inflammation. It can occur in various parts of the body. When it occurs in the eyelid and tissues in the front part of the eye area, it’s called pre-septal cellulitis. When it occurs behind ...

Central nervous system lymphoma is a form of lymphoma that invades the covering of the brain and spinal cord (the meninges). It is a type of cancer of white blood cells (lymphocytes). While lymphomas can occur anywhere in the body, ...

When one of the vessels that carry blood to your eye's retina gets blocked, it can cause you to lose your eyesight. This problem often happens suddenly and without any pain. This is called a central retinal artery occlusion (CRAO).

A cerebral abscess can cause your brain to swell, putting harmful pressure on brain tissue. An abscess can also keep blood from flowing to parts of your brain. If you develop this problem, you will need emergency treatment.

A cerebral aneurysm (also called an intracranial aneurysm or brain aneurysm) is a bulging, weakened area in the wall of an artery in the brain, resulting in an abnormal ballooning of the artery that is at risk for rupturing.

When an artery inside the skull becomes blocked by plaque or disease, it is called cerebral artery stenosis. Arteries anywhere in the body can become blocked. For example, carotid artery stenosis is a narrowing of the large artery in the...

A microembolism is a small particle, often a blood clot, that becomes caught while traveling through the bloodstream and can cause blockage in a blood vessel. When many of these occur in in the blood vessels of the brain, they are known ...

Cerebral palsy (CP) is a lifelong condition that affects how the brain and muscles communicate. CP affects body movement, muscle control, coordination, reflexes, posture, and balance.

Cerebral venous sinus thrombosis (CVST) occurs when a blood clot forms in the brain's venous sinuses. This prevents blood from draining out of the brain. As a result, blood cells may break and leak blood into the brain tissues, forming a...

Cerebrospinal fluid (CSF) leak occurs when there is a tear or hole in the membranes surrounding the brain or spinal cord, allowing the clear fluid that surrounds and cushions those organs to escape. Many CSF leaks heal on their own, but ...

Cerebrotendinous xanthomatosis (CTX) is a rare condition that affects the body's ability to metabolize fats known as cholesterols. Patients with CTX are unable to break down different forms of cholesterol, which build up in certain areas...

The cervix, or "neck" of the uterus, is the lowest part of the uterus, and is connected to the top of the vagina. The cervix is normally 3 cm long and 2-3 cm wide, and is visualized during a vaginal exam with the use of a speculum. The ...

Cervical cancer is cancer that starts in the cervix. Learn more about symptoms, diagnosis, and treatments.

The cervical spine refers to the seven spinal bones (vertebrae) in the neck. It supports the head and connects to the thoracic spine.

Cervicitis is irritation or infection of the cervix. It can be caused by a number of different sexually transmitted diseases.

Chagas disease is caused by a parasite. It is transmitted to people through the feces of insects. It is common in South and Central America and Mexico.

A chalazion (kuh-LAY-zee-un) is a slow-growing, painless lump in the eyelid that forms because of the swelling of an oil gland. It’s more common in adults between ages 30 and 50 than in children.

Charcot-Marie-Tooth disease is an inherited nerve defect that causes abnormalities in the nerves that supply your feet, legs, hands, and arms.

Chemical burns happen when a chemical gets into your child’s eye.

Chemotherapy, often called chemo, uses one or more drugs to kill cancer cells. Cancer cells often grow quickly. Chemotherapy slows this by blocking a cell's ability to split and reproduce.

Hair loss is a common side effect of chemotherapy. It can affect the hair on the head, and also the eyebrows, eyelashes, and facial and pubic hair. Not all chemotherapy causes hair loss. And not all children lose hair in the same way.