Ammonia is a chemical that both occurs naturally and can be created. It is a colorless gas — one part nitrogen and three parts hydrogen — with a foul smell that most people easily recognize.

An electrocardiogram, called an EKG or ECG, measures the electrical activity of the heart and collects data about heart's health. Typically, a doctor or technician places electrodes connected to a ...

A nodule is an abnormal tissue growth that can appear anywhere in the body and can form for various reasons. Depending on their location, nodules may not cause symptoms, and many people with nodules ...

Lymphoma is a cancer that originates in the lymphatic system, a vital part of the body’s immune defenses. This system includes lymph nodes, vessels, and tissues found in the bone marrow, spleen, ...

Fissured tongue is a common condition that describes a tongue with unique fissures or grooves that vary from person to person in size, location, and depth. Depending on the context, doctors also refer ...

Dystonic reactions are a form of secondary or acquired dystonia, the involuntary contraction of certain muscles. These reactions can affect several different parts of the body and can result from a ...

Muscle atrophy occurs when muscle mass decreases, causing limbs and other body parts to appear smaller than normal. Atrophy can result in symptoms such as weakness, balance problems, poor coordination ...

Exostosis is excess bone growth. With exostosis, bone grows outward from the original bone, causing it to thicken. In some cases, there's a palpable lump or area of thickness. Exostosis can be ...

Peripheral neuropathy is a broad term for any condition that damages the peripheral nerves that transfer sensory information and carry signals from the central nervous system in the brain and spinal ...

Choleric is one of the four cornerstones of humorism. Also called the humoral theory, this system of medicine attempted to explain many of the conditions that could affect the body. Though Ancient ...

The practice of bloodletting goes back 3,000 years. In fact, this ancient medical practice was so revered for centuries that it’s only since the 19th century that the practice fell into disfavor.

Blastocystis hominis is a single-celled, microscopic intestinal parasite. Whether blastocystis causes illness in people is controversial. The organism is found in both healthy people and those who ...