Anna Gora

There are a number of possible reasons for bleeding between periods, including hormonal changes, infections and certain medical conditions.

A buildup of dental plaque breaks down tooth enamel, leading to tooth decay, gum disease and other oral health conditions.

Having a stuffy nose often comes with pain and tenderness around your cheeks, eyes or forehead. But what do blocked sinuses look like inside your head?

Coming down with a cold or the flu can muffle your hearing, but why?

Heart murmurs are extra, unusual sounds heard during a heartbeat — but why do they happen?

After you've eaten beets, your poop and urine can take on a shocking red or pink color — but why?

The speed at which food moves through the digestive tract depends on many factors.

Several muscles could be called the "largest" in the body, depending on whether you're talking mass or surface area, but the body's smallest muscle has no competition.

Freckles can reappear or become darker after sun exposure and then fade in less-sunny seasons.

It's normal for you to occasionally get dizzy and for your vision to go dark when you stand up, but it can sometimes be a sign of a chronic health condition.

Stress can cause "nervous stomach," but what is the link between negative emotions and uncomfortable digestive symptoms?

From stress to dehydration, there are many reasons why some people's veins may be "hard to find" when they're getting an infusion or blood draw.

Knowing how to recognize and safely treat tick bites can help reduce your risk of developing tick-borne infectious diseases, such as Lyme disease and Rocky Mountain spotted fever.

Skin cancer, the uncontrolled growth of abnormal cells in the skin, is mainly caused by exposure to ultraviolet radiation from the sun and tanning equipment.

Lyme disease is an infection that is spread to humans through the bites of ticks carrying specific bacteria.

Discovered by sheer accident in the late 1920s, penicillin was the world's first antibiotic.