Dysfunction in the sacroiliac joint is thought to cause low back pain and/or leg pain. The leg pain can be particularly difficult and may feel similar to sciatica or pain caused by a lumbar disc herniation. The sacroiliac joint lies next...

A sacroiliac joint injection is used to diagnose or treat lower back pain that comes from your sacroiliac joint. This joint is the place where your spine connects to your pelvis. For the procedure, your healthcare provider injects ...

The sacrum is the triangular bone just below the lumbar vertebrae. The sacrum has five segments fused together into one large bone.

The most common problems in the salivary gland occur when the ducts become blocked and saliva cannot drain. Among the causes are dehydration, smoking and exposure to radiation. Most salivary tumors are noncancerous. Small blockages may ...

Salmonella is caused by the bacteria salmonella. Salmonella is a group of bacteria that can cause diarrhea in humans. There are many different kinds of salmonella bacteria.

Sarcomas affect people of all ages, races and sexes. They are quite rare in the United States, with about 5,500 new cases diagnosed every year. Sarcomas represent only one percent of all cancer cases. Sarcomas occur in the soft tissues ...

Detailed information on scabies, including symptoms, diagnosis, and treatment

Scabies is an infestation of tiny bugs called mites on the skin. It causes a small red rash and intense itching. This infection is very contagious. It often spreads from child to child while children are sleeping together in the same bed...

Scarlet fever is an infectious disease that causes a rash. It is caused by the same kind of bacteria that cause strep throat.

Schizophrenia is a complex brain disorder. It is caused by a chemical imbalance and often runs in families. This illness can't be cured but can be managed with medicine and therapy.

Schizophrenia is a serious mental illness. It is a long-lasting and disabling problem of the brain. A child with this disorder has unusual behavior and strange feelings.

These tumors come from the cells that form a protective sheath around the body's nerve fibers. They're usually benign and surgically removed when possible. They usually appear as a single tumor. Rarely will they develop into multiple ...

Sciatica, also called lumbar radiculopathy, is a pain that starts along your sciatic nerve, the largest nerve in the body. The pain goes from the back of your pelvis down the back of your thigh.

Scleral buckling is a type of eye surgery to fix a detached retina and restore vision.

Scleroderma is an ongoing (chronic) disease that causes abnormal growth of connective tissue. It can affect the joints, skin, and internal organs. It is degenerative and gets worse over time.

Scleroderma is an ongoing (chronic) disease that causes abnormal growth of connective tissue. It can affect the joints, skin, and internal organs. It is degenerative and gets worse over time.

A spine affected by scoliosis shows a sideways curvature and a rotation of the vertebrae, giving the appearance that the person is leaning to one side.

Scoliosis is a deformity of the backbone (spine). It's when the spine has a side-to-side curve. The curve of the spine measures 10 degrees or more.

Scrotal swelling is a common problem in baby boys and young boys. It can have many causes. These are often divided into painless and painful scrotal swelling.

Seasonal affective disorder (SAD) is a type of depression. It happens during certain seasons of the year, most often fall or winter. Here's what you need to know.

Detailed information on seborrheic dermatitis, including symptoms, diagnosis, and treatment

A seborrheic keratosis is a growth on the skin. The growth is not cancer (benign). It’s color can range from white, tan, brown, or black. Seborrheic keratoses often appear on a person’s chest, arms, back, or other areas. They’re very ...

A burn is damage to tissues of the body caused by contact with things such as heat, radiation, or chemicals. A second-degree burn affects the outer layer of skin (epidermis) and part of the inner layer of skin (dermis).

Multiple Sclerosis (MS) is a disease of the central nervous system (CNS), which is made up of the brain, spinal cord and optic nerve. This disorder causes destruction of the coating (myelin) that surrounds and protects nerve fibers ...

Secondhand smoke is the smoke you are exposed to when someone nearby is smoking. It includes the smoke exhaled by the smoker, and the smoke given off directly by the burning tobacco.

A seizure is usually caused by unusual electrical activity in the brain. There are many different types of seizures. These can affect different areas of the brain and body. When these seizures become more frequent or disruptive, the ...

Selective mutism is a rare condition when a child can’t speak in certain settings, but can speak fine in others. It can cause problems with school and social situations.

Evoked potentials studies measure electrical activity in the brain in response to stimulation of sight, sound, or touch.

A seizure is unusual electrical activity in the brain. Sensory seizures can affect any of the five senses: touch, taste, hearing, vision, and smell. A sensory seizure is a type of simple partial seizure.

Breast cancer can spread to the nearby tissue in the underarms (axillary). This tissue is known as lymph nodes. The first node in the group is known as a sentinel node. If no cancer is found in the first node, the cancer has probably not...