All Diseases

Chronic traumatic encephalopathy (CTE) results from blows to the head over a period of time that cause concussion (mild traumatic brain injury). These injuries lead to difficulties with thinking (cognition), emotions and behaviors that do not become noticeable until many years later. CTE can lead to physical problems as well. Not everyone who has one or more concussions develops CTE.

CTE involves progressive damage to nerve cells (neurodegenerative disease). The damage results in visible changes to the brain. Some of these changes can be seen with brain imaging, but a diagnosis at this time can be made only on inspection after death (autopsy). Researchers are working to find a way to diagnose CTE in those who have the disease while the individuals are still alive.

Originally called punch drunk syndrome (dementia pugilistica), CTE was first demonstrated in boxers. Doctors now know that other individuals who play a wide variety of sports that involve repeated blows to the head, such as football players, can develop CTE. Military personnel who have had blast injuries also are at risk.

Researchers do not yet fully understand CTE's prevalence and causes. There is no cure for CTE.

Churg-Strauss syndrome — also known as eosinophilic granulomatosis (gran-u-loe-muh-TOE-sis) with polyangiitis (pol-e-an-jee-I-tis) — is a disorder marked by blood vessel inflammation. This inflammation can restrict blood flow to vital organs and tissues, sometimes permanently damaging them.

Asthma is the most common sign of Churg-Strauss syndrome, but Churg-Strauss syndrome can cause a variety of problems, ranging from hay fever, rash and gastrointestinal bleeding to severe pain and numbness in your hands and feet. The wide range of signs and symptoms and their similarity to those of other disorders makes Churg-Strauss syndrome challenging to diagnose.

Churg-Strauss syndrome is rare and has no cure. But, your doctor can usually help you control symptoms with steroids and other powerful immunosuppressant drugs.

Claudication is pain caused by too little blood flow, usually during exercise. Sometimes called intermittent claudication, this condition generally affects the blood vessels in the legs, but claudication can affect the arms, too.

At first, you'll probably notice the pain only when you're exercising, but as claudication worsens, the pain may affect you even when you're at rest.

Although it's sometimes considered a disease, claudication is technically a symptom of a disease. Most often, claudication is a symptom of peripheral artery disease, a potentially serious but treatable circulation problem in which the vessels that supply blood flow to your legs or arms are narrowed.

Fortunately, with treatment, you may be able to maintain an active lifestyle without pain.

Cleft lip and cleft palate are openings or splits in the upper lip, the roof of the mouth (palate) or both. Cleft lip and cleft palate result when developing facial structures in an unborn baby don't close completely.

Cleft lip and cleft palate are among the most common birth defects. Cleft lip and cleft palate most commonly occur as isolated birth defects but are also associated with many inherited genetic conditions or syndromes.

Having a baby born with a cleft can be upsetting, but cleft lip and cleft palate can be corrected. In most babies, a series of surgeries can restore normal function and achieve a more normal appearance with minimal scarring.

Clubfoot describes a range of foot abnormalities usually present at birth (congenital) in which your baby's foot is twisted out of shape or position. In clubfoot, the tissues connecting the muscles to the bone (tendons) are shorter than usual. The term "clubfoot" refers to the way the foot is positioned at a sharp angle to the ankle, like the head of a golf club. Clubfoot is a fairly common birth defect and is usually an isolated problem for an otherwise healthy newborn.

Clubfoot can be mild or severe. About half of children with clubfoot have it in both feet. If your child has clubfoot, it will make it hard for him or her to walk normally, so doctors generally recommend treating it soon after birth.

Doctors are usually able to treat clubfoot successfully, though sometimes children need follow-up surgery later on.

Cluster headaches occur in cyclical patterns or clusters, which gives the condition its name. Cluster headache is one of the most painful types of headache.

Cluster headache commonly awakens you in the middle of the night with intense pain in or around one eye on one side of your head.

Bouts of frequent attacks, known as cluster periods, may last from weeks to months, usually followed by remission periods when the headache attacks stop completely. During remission, no headaches occur for months and sometimes even years.

Fortunately, cluster headache is rare and not life-threatening. Treatments can help make cluster headache attacks shorter and less severe. In addition, medications can help reduce the number of cluster headaches.

Coarctation (ko-ahrk-TAY-shun) of the aorta — or aortic coarctation — is a narrowing of the aorta, the large blood vessel that branches off your heart and delivers oxygen-rich blood to your body. When this occurs, your heart must pump harder to force blood through the narrow part of your aorta.

Coarctation of the aorta is generally present at birth (congenital). Coarctation of the aorta may range from mild to severe, and may not be detected until adulthood, depending on how narrowed the aorta is.

Coarctation of the aorta often occurs along with other heart defects. While treatment for coarctation of the aorta is usually successful, it's a condition that requires careful follow-up through infancy and throughout adulthood.

Cold sores — also called fever blisters — are tiny, fluid-filled lesions that occur on and around your lips. These blisters are often grouped together in patches. After the blisters break, a crust forms over the resulting sore. Cold sores usually heal within two weeks.

Cold sores spread from person to person by close personal contact, such as kissing. Cold sores are caused by a herpes simplex virus (HSV-1) closely related to the one that causes genital herpes (HSV-2). Both of these herpes simplex viruses can affect your mouth or your genitals, and can be spread via oral sex.

There's no cure for HSV infection and the blisters may recur sporadically — often in response to stress or a weakened immune system. Antiviral medications can help cold sores heal more quickly and may reduce the frequency of recurrences.

Cold urticaria (ur-tih-KAR-e-uh) is a skin reaction to cold. Skin that has been in contact with cold develops reddish, itchy welts (hives).

The severity of cold urticaria symptoms varies widely. Some people have minor reactions to cold, while others have severe reactions. Swimming in cold water is the most common cause of a whole-body (systemic) reaction. This could lead to very low blood pressure, fainting, shock and even death.

Cold urticaria occurs most frequently in young adults. And it generally clears up within a few years. If you think you have this condition, consult your doctor. Treatment for cold urticaria usually includes taking antihistamines and avoiding cold air and water.

Colic is a frustrating condition marked by predictable periods of significant distress in an otherwise well-fed, healthy baby. Babies with colic often cry more than three hours a day, three days a week for three weeks or longer. Nothing you do to try to help your baby during these episodes seems to bring any relief.

Colic can be distressing for both you and your baby. But take comfort: Colic is relatively short-lived. In a matter of weeks or months, the colic will end, and you'll have weathered one of the first major challenges of parenthood.