Nitric oxide isn’t a nutrient you’ll find on food packaging — but it plays a critical role in how your body moves, recovers, and circulates blood. This molecule helps blood vessels relax and widen, ...

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 ...

Lower back pain is extremely common, affecting millions of people every day. But what does it mean when the pain is felt only on one side? One-sided lower back pain could represent a minor issue that ...

Glomeruli are clusters of small blood vessels in the kidney that allow waste to pass from the blood and into the urine. Glomerulonephritis occurs when the glomeruli swell, damaging the kidneys and ...

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 ...

A tracheostomy is a surgical hole made at the front of the neck into the trachea or windpipe. A surgeon will create this hole when the airway is blocked or damaged, preventing air from reaching the ...

Usually, the testicles hang inside the scrotum, the loose bag of skin behind the penis. However, retractile testicles move up out of the scrotum and into the groin. Retractile testicles are most ...

Pneumonia occurs when bacteria enters your lungs, when food, stomach acid, or your saliva goes down or comes up the esophagus -- the wrong channel. This condition is called pulmonary aspiration, and ...

Naegleria fowleri is a rare but deadly organism that lives in warm freshwater like lakes, rivers, and hot springs. Most people recognize this dangerous organism by its common name: the brain-eating ...

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, ...

Swearing has caught the attention of both psychologists and researchers over the years. Is this taboo language harmful? Is swearing getting worse? Does swearing influence children? Is swearing linked ...

The good news: blue waffle disease isn't a real STI. Back in 2010, this urban legend began with a photograph showing an infected vagina with a blue labia. While there's no definitive information about ...