All Diseases

A woman's sexual desires naturally fluctuate over the years. Highs and lows commonly coincide with the beginning or end of a relationship or with major life changes, such as pregnancy, menopause or illness. Some antidepressants and anti-seizure medications also can cause low sex drive in women.

If you have a persistent or recurrent lack of interest in sex that causes you personal distress, you may have hypoactive sexual desire disorder.

But you don't have to meet this medical definition to seek help. If you are bothered by a low sex drive or decreased sex drive, there are lifestyle changes and sex techniques that may put you in the mood more often. Some medications may offer promise as well.

Low sperm count means that the fluid (semen) you ejaculate during an orgasm contains fewer sperm than normal. A low sperm count is also called oligospermia (ol-ih-go-SPUR-me-uh). A complete absence of sperm is called azoospermia. Your sperm count is considered lower than normal if you have fewer than 15 million sperm per milliliter of semen.

Having a low sperm count decreases the odds that one of your sperm will fertilize your partner's egg, resulting in pregnancy. Nonetheless, many men who have a low sperm count are still able to father a child.

Lung cancer is a type of cancer that begins in the lungs. Your lungs are two spongy organs in your chest that take in oxygen when you inhale and release carbon dioxide when you exhale.

Lung cancer is the leading cause of cancer deaths in the United States, among both men and women. Lung cancer claims more lives each year than do colon, prostate, ovarian and breast cancers combined.

People who smoke have the greatest risk of lung cancer. The risk of lung cancer increases with the length of time and number of cigarettes you've smoked. If you quit smoking, even after smoking for many years, you can significantly reduce your chances of developing lung cancer.

Lupus is a chronic inflammatory disease that occurs when your body's immune system attacks your own tissues and organs. Inflammation caused by lupus can affect many different body systems — including your joints, skin, kidneys, blood cells, brain, heart and lungs.

Lupus can be difficult to diagnose because its signs and symptoms often mimic those of other ailments. The most distinctive sign of lupus — a facial rash that resembles the wings of a butterfly unfolding across both cheeks — occurs in many but not all cases of lupus.

Some people are born with a tendency toward developing lupus, which may be triggered by infections, certain drugs or even sunlight. While there's no cure for lupus, treatments can help control symptoms.

Lyme disease is the most common tick-borne illness in North America and Europe. Lyme disease is caused by the bacterium Borrelia burgdorferi. Deer ticks, which feed on the blood of animals and humans, can harbor the bacteria and spread it when feeding.

You're more likely to get Lyme disease if you live or spend time in grassy and heavily wooded areas where ticks carrying the disease thrive. It's important to take common-sense precautions in areas where Lyme disease is prevalent.

If you're treated with appropriate antibiotics in the early stages of the disease, you're likely to recover completely. In later stages, response to treatment may be slower, but the majority of people with Lyme disease recover completely with appropriate treatment.

Lymphedema refers to swelling that generally occurs in one of your arms or legs. Sometimes both arms or both legs swell.

Lymphedema is most commonly caused by the removal of or damage to your lymph nodes as a part of cancer treatment. It results from a blockage in your lymphatic system, which is part of your immune system. The blockage prevents lymph fluid from draining well, and the fluid buildup leads to swelling.

There's no cure for lymphedema. But it can be managed with early diagnosis and diligent care of your affected limb.

Lynch syndrome is an inherited condition that increases your risk of colon cancer and other cancers. Lynch syndrome has historically been known as hereditary nonpolyposis colorectal cancer (HNPCC).

A number of inherited syndromes can increase your risk of colon cancer, but Lynch syndrome is the most common. Doctors estimate that about 3 out of every 100 colon cancers are caused by Lynch syndrome.

Families that have Lynch syndrome usually have more cases of colon cancer than would typically be expected. Lynch syndrome also causes colon cancer to occur at an earlier age than it might in the general population.

Malaria is a disease caused by a parasite, transmitted by the bite of infected mosquitoes. Malaria produces recurrent attacks of chills and fever. Malaria kills an estimated 1 million people each year worldwide.

While the disease is uncommon in temperate climates, malaria is still prevalent in tropical and subtropical countries. World health officials are trying to reduce the incidence of malaria by distributing bed nets to help protect people from mosquito bites as they sleep. Scientists around the world are working to develop a vaccine to prevent malaria.

If you're traveling to locations where malaria is common, take preventive medicine before, during and after your trip. Many malaria parasites are now immune to the most common drugs used to treat the disease.

Male breast cancer is a rare cancer that forms in the breast tissue of men. Though breast cancer is most commonly thought of as a woman's disease, male breast cancer does occur.

Male breast cancer is most common in older men, though it can occur at any age.

Men diagnosed with male breast cancer at an early stage have a good chance for a cure. Still, many men delay seeing their doctors if they notice one of the usual signs or symptoms, such as a breast lump. For this reason, many male breast cancers are diagnosed when the disease is more advanced.

Male hypogonadism is a condition in which the body doesn't produce enough testosterone — the hormone that plays a key role in masculine growth and development during puberty — or has an impaired ability to produce sperm or both.

You may be born with male hypogonadism, or it can develop later in life from injury or infection. The effects — and what you can do about them — depend on the cause and at what point in your life male hypogonadism occurs. Some types of male hypogonadism can be treated with testosterone replacement therapy.