ScienceInsights

Cold sores typically clear up in 8–10 days. Learn what affects healing time, when you're contagious, and how much treatments actually help.

At one month, babies see best about 8–12 inches away. Here's what they can actually perceive and how you can support their developing vision.

Once menopause is confirmed, natural pregnancy isn't possible—but perimenopause is trickier. Here's what you need to know about fertility and birth control timing.

Rashes after a fever are often harmless and common, but some need medical attention. Learn what causes them and when to see a doctor.

Upper stomach pain after eating is often caused by acid reflux, gastritis, or gallbladder issues. Learn what your symptoms may mean and when to see a doctor.

Syphilis symptoms can appear within weeks or go unnoticed entirely. Learn when to get tested and what a reliable timeline looks like.

Most adults need 1–2 hours of deep sleep per night. Learn what affects it, how it changes with age, and simple ways to get more of it.

Side heel pain can come from several conditions, from tendonitis to stress fractures. Learn what might be causing yours and how to tell the difference.

Brown spotting before your period is usually old blood from hormone shifts, but it can also point to ovulation, birth control, or other causes worth knowing.

Nighttime leg aches can stem from muscle cramps, restless legs, or poor circulation. Learn what's likely causing yours and how to find relief.