All Diseases

Kleptomania (klep-toe-MAY-nee-uh) is the recurrent failure to resist urges to steal items that you generally don't really need and that usually have little value. Kleptomania is a serious mental health disorder that can cause much emotional pain to you and your loved ones if not treated.

Kleptomania is a type of impulse control disorder — a disorder that's characterized by problems with emotional or behavioral self-control. If you have an impulse control disorder, you have difficulty resisting the temptation or drive to perform an act that's excessive or harmful to you or someone else.

Many people with kleptomania live lives of secret shame because they're afraid to seek mental health treatment. Although there's no cure for kleptomania, treatment with medication or psychotherapy may be able to help end the cycle of compulsive stealing.

Klinefelter syndrome is a genetic condition that results when a boy is born with an extra copy of the X chromosome. Klinefelter syndrome is a common genetic condition affecting males.

Klinefelter syndrome adversely affects testicular growth, and this can result in smaller than normal testicles. This can lead to lower production of the sex hormone testosterone. Klinefelter syndrome may also cause reduced muscle mass, reduced body and facial hair, and enlarged breast tissue. The effects of Klinefelter syndrome vary, and not everyone with it develops these signs and symptoms.

Klinefelter syndrome often isn't diagnosed until adulthood. Most men with Klinefelter syndrome produce little or no sperm. But assisted reproductive procedures may make it possible for some men with Klinefelter syndrome to father children.

Knee bursitis is inflammation of a bursa located near your knee joint. A bursa is a small fluid-filled, pad-like sac that reduces friction and cushions pressure points between your bones and the tendons and muscles near your joints.

Each of your knees has 11 bursae. While any of these bursae can become inflamed, knee bursitis most commonly occurs over the kneecap or on the inner side of your knee below the joint.

Knee bursitis causes pain and can limit your mobility. Treatment for knee bursitis often includes a combination of self-care practices and doctor-administered treatments to alleviate pain and inflammation.

Knee pain is a common complaint that affects people of all ages. Knee pain may be the result of an injury, such as a ruptured ligament or torn cartilage. Medical conditions — including arthritis, gout and infections — also can cause knee pain.

Many types of minor knee pain respond well to self-care measures. Physical therapy and knee braces also can help relieve knee pain. In some cases, however, your knee may require surgical repair.

Krabbe (KRAH-buh) disease is an inherited disorder that destroys the protective coating (myelin) of nerve cells in the brain and throughout the nervous system.

In most cases, signs and symptoms of Krabbe disease develop in babies before 6 months of age, and the disease usually results in death by age 2. When it develops in older children and adults, the course of the disease can vary greatly.

There's no cure for Krabbe disease, and treatment focuses on supportive care. However, stem cell transplants have shown some success in infants who are treated before the onset of symptoms and in some older children and adults.

Krabbe disease affects about 1 in 100,000 people in the United States. It is also known as globoid cell leukodystrophy.

Kyphosis is a forward rounding of the back. Some rounding is normal, but the term "kyphosis" usually refers to an exaggerated rounding of the back. While kyphosis can occur at any age, it's most common in older women.

Age-related kyphosis often occurs after osteoporosis weakens spinal bones to the point that they crack and compress. Other types of kyphosis are seen in infants or teens due to malformation of the spine or wedging of the spinal bones over time.

Mild kyphosis causes few problems, but severe cases can cause pain and be disfiguring. Treatment for kyphosis depends on your age, the cause of the curvature and its effects.

Lactose intolerance, also called lactase deficiency, means you aren't able to fully digest the milk sugar (lactose) in dairy products. It's usually not dangerous, but symptoms of lactose intolerance can be uncomfortable.

A deficiency of lactase — an enzyme produced by the lining of your small intestine — is usually responsible for lactose intolerance. Many people have low levels of lactase, but only those who also have associated signs and symptoms have, by definition, lactose intolerance.

You can control symptoms of lactose intolerance by carefully choosing a diet that limits dairy products.

Laryngitis is an inflammation of your voice box (larynx) from overuse, irritation or infection.

Inside the larynx are your vocal cords — two folds of mucous membrane covering muscle and cartilage. Normally, your vocal cords open and close smoothly, forming sounds through their movement and vibration.

But in laryngitis, your vocal cords become inflamed or irritated. This swelling causes distortion of the sounds produced by air passing over them. As a result, your voice sounds hoarse. In some cases of laryngitis, your voice can become almost undetectable.

Laryngitis may be short-lived (acute) or long lasting (chronic). Most cases of laryngitis are triggered by temporary viral infection or vocal strain and aren't serious. Persistent hoarseness can sometimes signal a more serious underlying medical condition.

Latex allergy is a reaction to certain proteins found in natural rubber latex, a product made from a milky fluid from rubber trees. If you have a latex allergy, your body mistakes latex for a harmful substance.

Latex allergy may cause allergic reactions ranging from skin irritation to anaphylaxis, a potentially life-threatening condition. Your doctor can determine if you have a latex allergy or if you're at risk of developing a latex allergy.

Understanding latex allergy and knowing common sources of latex can help you prevent allergic reactions.

Lazy eye (amblyopia) is decreased vision that results from abnormal visual development in infancy and early childhood. Although lazy eye usually affects only one eye, it can affect both eyes. Lazy eye is the leading cause of decreased vision among children. Left untreated, vision loss may range from mild to severe.

With lazy eye, there may not be an obvious abnormality of the eye. Lazy eye develops when nerve pathways between the brain and the eye aren't properly stimulated. As a result, the brain favors one eye, usually due to poor vision in the other eye. The weaker eye tends to wander. Eventually, the brain may ignore the signals received from the weaker — or lazy — eye.

Usually doctors can correct lazy eye with eye patches, eyedrops, and glasses or contact lenses. Sometimes lazy eye requires surgical treatment.