All Diseases

Sweating and body odor are facts of life for most people. Heavy perspiration and body odor can happen when you exercise, when you're too warm, or when you're nervous, anxious or under stress.

Your body has two main types of sweat glands, and they produce two very different types of sweat. Both types are odorless, but the type of sweat produced in your armpits and groin smells bad when it combines with bacteria found normally on your skin.

Unusual changes in sweating — either excessive perspiration (hyperhidrosis) or little or no perspiration (anhidrosis) — can be cause for concern. Likewise, changes in body odor may be a sign of a medical problem.

For normal sweating and body odor, however, lifestyle and home treatments can effectively manage your symptoms.

Sweet's syndrome — also known as acute febrile neutrophilic dermatosis — is a rare skin condition marked by fever and painful skin lesions that appear mainly on your arms, neck, face and back.

The exact cause of Sweet's syndrome isn't always known. In some people, it's triggered by an infection, illness or certain medications. Sweet's syndrome can also occur with some types of cancer.

The most common treatment for Sweet's syndrome is corticosteroid pills, such as prednisone. Signs and symptoms often disappear just a few days after treatment begins, but recurrence is common.

Swimmer's ear is an infection in the outer ear canal, which runs from your eardrum to the outside of your head. It's often brought on by water that remains in your ear after swimming, creating a moist environment that aids bacterial growth.

Putting fingers, cotton swabs or other objects in your ears also can lead to swimmer's ear by damaging the thin layer of skin lining your ear canal.

Swimmer's ear is also known as acute external otitis or otitis externa. The most common cause of this infection is bacteria invading the skin inside your ear canal. Usually you can treat swimmer's ear with eardrops. Prompt treatment can help prevent complications and more-serious infections.

Swimmer's itch is an itchy rash that can occur after you go swimming or wading outdoors. Also known as cercarial dermatitis, swimmer's itch is most common in freshwater lakes and ponds, but it occasionally occurs in salt water.

Swimmer's itch is an allergic reaction to microscopic parasites that burrow into your skin. The parasites associated with swimmer's itch normally live in waterfowl and some animals that live near the water. Humans aren't suitable hosts, so the parasites soon die while still in your skin.

Although uncomfortable, swimmer's itch is usually short-lived. The rash typically clears up on its own within a few days. In the meantime, you can control itching with over-the-counter or prescription medications.

Technically, the term "swine flu" refers to influenza in pigs. Occasionally, pigs transmit influenza viruses to people, mainly to hog farmers and veterinarians. Less often, someone infected passes the infection to others.

The human respiratory infection caused by a particular influenza virus H1N1 strain — popularly known as swine flu — was first recognized in spring 2009. A few months after the first swine flu cases were reported, rates of confirmed H1N1-related illness were increasing in much of the world. As a result, the World Health Organization declared the infection a global pandemic.

The pandemic was declared over in August 2010. Currently, H1N1 is still circulating in humans as a seasonal flu virus and is included in the seasonal flu vaccine.

Swollen lymph nodes usually occur as a result of exposure to bacteria or viruses. When swollen lymph nodes are caused by an infection, this is known as lymphadenitis (lim-fad-uh-NIE-tis). Rarely, swollen lymph nodes are caused by cancer.

Your lymph nodes, also called lymph glands, play a vital role in your body's ability to fight off viruses, bacteria and other causes of illnesses. Common areas where you might notice swollen lymph nodes include your neck, under your chin, in your armpits and in your groin.

In some cases, the passage of time and warm compresses may be all you need to treat swollen lymph nodes. Treatment for lymphadenitis depends on the cause.

Syphilis is a bacterial infection usually spread by sexual contact. The disease starts as a painless sore — typically on your genitals, rectum or mouth. Syphilis spreads from person to person via skin or mucous membrane contact with these sores.

After the initial infection, the syphilis bacteria can lie dormant in your body for decades before becoming active again. Early syphilis can be cured, sometimes with a single injection of penicillin. Without treatment, syphilis can severely damage your heart, brain or other organs, and can be life-threatening.

Syphilis rates in the United States have been declining among women since 2010, but rising among men, particularly men who have sex with men. The genital sores associated with syphilis can make it easier to become infected with HIV, the virus that causes AIDS.

Syringomyelia (sih-ring-go-my-E-lee-uh) is the development of a fluid-filled cyst (syrinx) within your spinal cord. Over time, the cyst may enlarge, damaging your spinal cord and causing pain, weakness and stiffness, among other symptoms.

Syringomyelia has several possible causes, though the majority of cases are associated with a condition in which brain tissue protrudes into your spinal canal (Chiari malformation).

Other causes of syringomyelia include spinal cord tumors, spinal cord injuries and damage caused by inflammation around your spinal cord.

If syringomyelia isn't causing any problems, monitoring the condition may be all that's necessary. But if you're bothered by symptoms, you may need surgery.

Tachycardia is a faster than normal heart rate at rest. A healthy adult heart normally beats 60 to 100 times a minute when a person is at rest. If you have tachycardia (tak-ih-KAHR-dee-uh), the heart rate in the upper chambers or lower chambers of the heart, or both, is increased.

Heart rate is controlled by electrical signals sent across heart tissues. Tachycardia occurs when an abnormality in the heart produces rapid electrical signals.

In some cases, tachycardia may cause no symptoms or complications. However, tachycardia can seriously disrupt normal heart function, increase the risk of stroke, or cause sudden cardiac arrest or death.

Treatments may help control a rapid heartbeat or manage diseases contributing to tachycardia.

Takayasu's arteritis (tah-kah-YAH-sooz ahr-tuh-RIE-tis) is a rare type of vasculitis, a group of disorders that cause blood vessel inflammation. In Takayasu's arteritis, the inflammation primarily damages the aorta — the large artery that carries blood from your heart to the rest of your body — and the aorta's main branches.

The disease can lead to blockages or narrowed arteries (stenosis) or abnormally dilated arteries (aneurysms). Takayasu's arteritis can also lead to arm or chest pain and high blood pressure and eventually to heart failure or stroke.

The goal of treatment is to relieve inflammation in the arteries and prevent potential complications. Even with early detection and treatment, however, Takayasu's arteritis can be challenging to manage.