All Diseases

Autism spectrum disorder is a serious neurodevelopmental disorder that impairs a child's ability to communicate and interact with others. It also includes restricted repetitive behaviors, interests and activities. These issues cause significant impairment in social, occupational and other areas of functioning.

Autism spectrum disorder (ASD) is now defined by the American Psychiatric Association's Diagnosis and Statistical Manual of Mental Disorders (DSM-5) as a single disorder that includes disorders that were previously considered separate — autism, Asperger's syndrome, childhood disintegrative disorder and pervasive developmental disorder not otherwise specified.

The term "spectrum" in autism spectrum disorder refers to the wide range of symptoms and severity. Although the term "Asperger's syndrome" is no longer in the DSM, some people still use the term, which is generally thought to be at the mild end of autism spectrum disorder.

The number of children diagnosed with autism spectrum disorder is rising. It's not clear whether this is due to better detection and reporting or a real increase in the number of cases, or both.

While there is no cure for autism spectrum disorder, intensive, early treatment can make a big difference in the lives of many children.

Autoimmune hepatitis is inflammation in your liver that occurs when your body's immune system attacks your liver. Although the cause of autoimmune hepatitis isn't entirely clear, some diseases, toxins and drugs may trigger autoimmune hepatitis in susceptible people, especially women.

Untreated autoimmune hepatitis can lead to scarring of the liver (cirrhosis) and eventually to liver failure. When diagnosed and treated early, however, autoimmune hepatitis often can be controlled with drugs that suppress the immune system.

A liver transplant may be an option when autoimmune hepatitis doesn't respond to drug treatments or when liver disease is advanced.

Autonomic neuropathy is a nerve disorder that affects involuntary body functions, including heart rate, blood pressure, perspiration and digestion.

It isn't a specific disease. Autonomic neuropathy refers to damage to the autonomic nerves. This damage disrupts signals between the brain and portions of the autonomic nervous system, such as the heart, blood vessels and sweat glands. This can cause decreased or abnormal performance of one or more involuntary body functions.

Autonomic neuropathy can be a complication of a number of diseases and conditions. And some medications can cause autonomic neuropathy as a side effect. Signs, symptoms and treatment of autonomic neuropathy vary depending on the cause, and on which nerves are affected.

Avascular necrosis is the death of bone tissue due to a lack of blood supply. Also called osteonecrosis, avascular necrosis can lead to tiny breaks in the bone and the bone's eventual collapse.

The blood flow to a section of bone can be interrupted if the bone is fractured or the joint becomes dislocated. Avascular necrosis of bone is also associated with long-term use of high-dose steroid medications and excessive alcohol intake.

The hip is the joint most commonly affected by avascular necrosis. While avascular necrosis of bone can happen to anyone, it usually occurs in men between the ages of 30 and 60.

Baby acne is acne that develops on a newborn's skin. Baby acne can occur anywhere on the face, but usually appears on the cheeks, nose and forehead. Baby acne is common — and temporary. There's little you can do to prevent baby acne. The best treatment for baby acne is usually none at all.

Back pain is a common complaint. Most people in the United States will experience low back pain at least once during their lives. Back pain is one of the most common reasons people go to the doctor or miss work.

On the bright side, you can take measures to prevent or lessen most back pain episodes. If prevention fails, simple home treatment and proper body mechanics will often heal your back within a few weeks and keep it functional for the long haul. Surgery is rarely needed to treat back pain.

Bacterial vaginosis is a type of vaginal inflammation that results from the overgrowth of one of several types of bacteria normally present in the vagina, upsetting the natural balance of vaginal bacteria.

Women in their reproductive years are most commonly affected by bacterial vaginosis, but any woman can experience the condition. Doctors don't know exactly why bacterial vaginosis develops, but certain activities, such as unprotected sexual intercourse or frequent douching, put you at higher risk of the condition.

Bad breath, also called halitosis, can be embarrassing and in some cases may even cause anxiety. It's no wonder that store shelves are overflowing with gum, mints, mouthwashes and other products designed to fight bad breath. But many of these products are only temporary measures because they don't address the cause of the problem.

Certain foods, health conditions and habits are among the causes of bad breath. In many cases, you can improve bad breath with consistent proper dental hygiene. If simple self-care techniques don't solve the problem, see your dentist or physician to be sure a more serious condition isn't causing your bad breath.

Bags under eyes — mild swelling or puffiness under the eyes — are common as you age. With aging, the tissues around your eyes, including some of the muscles supporting your eyelids, weaken. Normal fat that helps support the eyes can then move into the lower eyelids, causing the lids to appear puffy. Fluid also may accumulate in the space below your eyes, adding to the swelling.

Bags under eyes are usually a cosmetic concern and rarely a sign of a serious underlying medical condition. At-home remedies, such as cool compresses, can help improve the appearance of bags under eyes. For persistent or bothersome under-eye puffiness, cosmetic treatments are available.

A Baker's cyst is a fluid-filled cyst that causes a bulge and a feeling of tightness behind your knee. The pain can get worse when you fully flex or extend your knee or when you're active.

A Baker's cyst, also called a popliteal (pop-LIT-e-ul) cyst, is usually the result of a problem with your knee joint, such as arthritis or a cartilage tear. Both conditions can cause your knee to produce too much fluid, which can lead to a Baker's cyst.

Although a Baker's cyst may cause swelling and make you uncomfortable, treating the probable underlying problem usually provides relief.