Biology Insights

Toenail fungus spreads through small nail cracks in warm, damp places. Learn what raises your risk and why it tends to come back.

Persistent dry mouth is often caused by medications, health conditions, or mouth breathing — and it can affect your teeth. Here's how to find relief.

Medicare covers kidney transplants, but out-of-pocket costs can still add up. Here's what to expect for surgery, anti-rejection drugs, and more.

An armpit lump is usually harmless, but knowing the common causes—from swollen lymph nodes to cysts—can help you decide when to see a doctor.

MRSA in the nose can cause sores, crusting, and pain that won't heal. Learn how to spot it, how it's tested, and when to see a doctor.

Most 6-month-olds should only be in a car seat for about 2 hours at a time. Here's why it matters and how to plan trips safely.

Heel pain has several possible causes depending on where it hurts. Learn what's likely behind your pain and what actually helps it feel better.

At 7 months, babies can see clearly up to a few feet away. Learn what's normal for their vision, color perception, and depth awareness at this stage.

Tweaked your back? Here's what to actually do in the first 48 hours to ease pain and speed up recovery.

From in-office treatments to baking soda, here's what actually works for yellow teeth and what's better left alone.

Eye bags aren't all the same, and neither are the fixes. Learn which treatments actually work for puffiness versus permanent under-eye bags.

Hand, foot, and mouth disease usually starts with mouth sores and fever before any rash appears. Here's what to look for in those first few days.

Knee popping is often harmless, but it can sometimes signal cartilage wear or a meniscus tear. Learn what's causing the noise and when to see a doctor.

Learn how facial melanoma can look across different types and skin tones, and which changes in a spot are worth getting checked by a doctor.

Peeling sunburn skin is tempting to pick at, but there's a better way. Learn what actually helps healing and what to avoid.

Feeling dizzy or faint from low blood pressure? Learn practical ways to raise it quickly at home, from hydration tips to movement changes and when to see a doctor.

Creatine monohydrate is the most researched form for muscle growth. Learn how it works, how to dose it, and what results you can realistically expect.

Daily tretinoin use is possible for many people, but your skin needs time to adjust. Here's how to know if you're using it too often.