All Diseases

A sore throat is pain, scratchiness or irritation of the throat that often worsens when you swallow.

A sore throat is the primary symptom of pharyngitis — inflammation of the throat (pharynx). But the terms "sore throat" and "pharyngitis" are often used interchangeably.

The most common cause of a sore throat is a viral infection, such as a cold or the flu. A sore throat caused by a virus resolves on its own with at-home care. Strep throat (streptococcal infection), a less common type of sore throat caused by bacteria, requires additional treatment with antibiotic drugs to prevent complications.

Other less common causes of sore throat may require more complex treatment.

Allergy to soy, a product of soybeans, is a common food allergy. Often, soy allergy starts in infancy with reaction to soy-based infant formula. Although most children outgrow soy allergy, some carry the allergy into adulthood.

Mild signs and symptoms of soy allergy include hives or itching in and around the mouth. In rare cases, soy allergy can cause a life-threatening allergic reaction (anaphylaxis).

If you or your child has a reaction to soy, let your doctor know. Tests can help confirm a soy allergy.

Having a soy allergy means avoiding products that contain soy, which can be difficult. Many foods, such as meat products, bakery goods, chocolate and breakfast cereals, may contain soy.

A spermatocele (SPUR-muh-toe-seel) is an abnormal sac (cyst) that develops in the epididymis — the small, coiled tube located on the upper testicle that collects and transports sperm. Noncancerous and generally painless, a spermatocele usually is filled with milky or clear fluid that might contain sperm.

The exact cause of spermatoceles is unknown but might be due to a blockage in one of the tubes that transports sperm.

Spermatoceles, sometimes called spermatic cysts, are common. They typically don't reduce fertility or require treatment. If a spermatocele grows large enough to cause discomfort, your doctor might suggest surgery.

Spider bites are usually harmless. In fact, many bites attributed to spiders turn out to have been inflicted by other bugs. Skin infections also have been mistaken for spider bites.

Only a few types of spiders have fangs long enough to penetrate human skin and venom strong enough to severely affect a human being. In the U.S., these include the black widow spider and the brown recluse spider.

Black widow spider bites can cause severe abdominal pain and cramping, while brown recluse spider bites can cause the skin around the bite to die. Both these spiders generally live in undisturbed areas, such as attics or sheds, and don't bite unless threatened.

Spina bifida is part of a group of birth defects called neural tube defects. The neural tube is the embryonic structure that eventually develops into the baby's brain and spinal cord and the tissues that enclose them.

Normally, the neural tube forms early in the pregnancy and closes by the 28th day after conception. In babies with spina bifida, a portion of the neural tube fails to develop or close properly, causing defects in the spinal cord and in the bones of the spine.

Spina bifida occurs in various forms of severity. When treatment for spina bifida is necessary, it's done surgically, although such treatment doesn't always completely resolve the problem.

A spinal cord injury — damage to any part of the spinal cord or nerves at the end of the spinal canal — often causes permanent changes in strength, sensation and other body functions below the site of the injury.

If you've recently experienced a spinal cord injury, it might seem like every aspect of your life will be affected.

Many scientists are optimistic that advances in research will someday make the repair of spinal cord injuries possible. Research studies are ongoing around the world. In the meantime, treatments and rehabilitation allow many people with a spinal cord injury to lead productive, independent lives.

Spinal headaches occur in up to 40 percent of those who undergo a spinal tap (lumbar puncture) or spinal anesthesia. Both procedures require a puncture of the tough membrane that surrounds the spinal cord and, in the lower spine, the lumbar and sacral nerve roots.

During a spinal tap, a sample of cerebrospinal fluid is withdrawn from your spinal canal. During spinal anesthesia, medication is injected into your spinal canal to numb the nerves in the lower half of your body. If spinal fluid leaks through the tiny puncture site, you may develop a spinal headache.

Most spinal headaches — also known as post-lumbar puncture headaches — resolve on their own with no treatment. However, spinal headaches lasting 24 hours or more may need treatment.

Spinal stenosis is a narrowing of the open spaces within your spine, which can put pressure on your spinal cord and the nerves that travel through the spine. Spinal stenosis occurs most often in the neck and lower back.

While some people have no signs or symptoms, spinal stenosis can cause pain, numbness, muscle weakness, and problems with bladder or bowel function.

Spinal stenosis is most commonly caused by wear-and-tear changes in the spine related to aging. In severe cases of spinal stenosis, doctors may recommend surgery to create additional space for the spinal cord or nerves.

Spontaneous coronary artery dissection — sometimes referred to as SCAD — is a rare emergency condition that occurs when a tear forms in one of the blood vessels in the heart.

Spontaneous coronary artery dissection (SCAD) can slow or block blood flow to the heart, causing a heart attack, abnormalities in heart rhythm and sudden death.

Spontaneous coronary artery dissection (SCAD) tends to affect people ages 30 to 50, though it can occur at any age. People who develop spontaneous coronary artery dissection (SCAD) are often healthy, and many don't have risk factors for heart disease, such as high blood pressure and diabetes.

Spontaneous coronary artery dissection (SCAD) can lead to sudden death if it isn't diagnosed and treated promptly. For this reason, seek emergency attention if you experience heart attack signs and symptoms — even if you think you aren't at risk for a heart attack.

A sprained ankle is an injury that occurs when you roll, twist or turn your ankle in an awkward way. This can stretch or tear the tough bands of tissue (ligaments) that help hold your ankle bones together.

Ligaments help stabilize joints, preventing excessive movement. A sprained ankle occurs when the ligaments are forced beyond their normal range of motion. Most sprained ankles involve injuries to the ligaments on the outer side of the ankle.

Treatment for a sprained ankle depends on the severity of the injury. Although self-care measures and over-the-counter pain medications may be all you need, a medical evaluation might be necessary to reveal how badly you've sprained your ankle and to put you on the path to recovery.