Thoracic outlet syndrome is a variety of symptoms that happen from a narrowing of your thoracic outlet—the space between your collarbone and your first rib. It can result from injury, disease, or a problem you had from birth.

Obstructive sleep apnea occurs when your breathing stops briefly during sleep. This can occur when something is blocking your airway. The stopped breathing can occur many times a night causing snoring, and daytime fatigue.

Takotsubo cardiomyopathy (TCM) is a type of heart condition. It causes sudden chest pain. The symptoms of TCM can look like a heart attack.

Takayasu's arteritis is an autoimmune disease. It causes inflammation of the large arteries. It's a rare disease that's most common in women and people of Asian descent.

A subdural hematoma is a buildup of blood on the surface of the brain. Read on for details about this condition, including causes, who's at risk, symptoms, diagnosis, and treatment.

A subconjunctival hemorrhage is when a blood vessel breaks open in the white of the eye. It causes a bright red patch in the white of the eye.

Sixth nerve palsy occurs when the sixth cranial nerve is damaged or doesn't work right. It's also known as the abducens nerve. This condition causes problems with eye movement.

Sinus bradycardia is a type of slow heartbeat. Read on to learn more about this condition, including causes, risk factors, symptoms, diagnosis, and treatment.

Simple kidney cysts are fluid-filled sacs that form in your kidneys. These cysts usually don’t affect how the kidneys function.

When you have a shoulder separation injury, trauma damages the ligaments surrounding your acromioclavicular (AC) joint. This is where your collarbone (clavicle) meets your shoulder blade (scapula). If your injury is severe, part of your shoulder blade actually separates from your collarbone.