Biology Insights

Conception rarely happens on the day of intercourse. Learn how sperm survival and ovulation timing affect when fertilization actually occurs.

Plan B works best within 72 hours, but timing, body weight, and other factors affect how well it works. Here's what you need to know.

Apple cider vinegar may help with blood sugar and PCOS, but its benefits for women are more modest than claimed. Here's what the evidence actually shows.

Hair loss has many names and causes. Learn the difference between common types of alopecia and when thinning or shedding warrants a visit to your doctor.

How long cannabis stays in your system depends on the test type, your body fat, and how you consumed it. Here's what the science actually says.

Most cats need pain meds for about 3 days after spaying. Learn how to tell if your cat is still uncomfortable and when it's safe to stop the medication.

STD tests work best within specific windows after exposure. Here's how long to wait for accurate results for HIV, herpes, chlamydia, and more.

Woke up with a stiff neck? Learn what causes it, how to ease the pain quickly, and simple ways to stop it from happening again.

Nicotine cravings are most intense in the first week but can linger for months. Here's what to realistically expect after quitting.

Foot neuropathy rarely has one cure — treatment depends on the cause. Learn what actually helps, from blood sugar control to nerve surgery.

Protein needs shift in your late 40s. Here's how much a 48-year-old woman actually needs, when to eat it, and the best food sources to hit your daily goal.

From honey to steam to OTC meds, here's what actually helps a cough and when it's time to see a doctor.

Razor burn usually clears up in a few days, but the timeline depends on your skin and how you treat it. Here's what helps it heal faster.

Plantar warts can be stubborn, but the right treatment makes a difference. Learn which remedies actually work and when to see a doctor.

Bleeding gums or bad breath could point to gum disease. Learn the signs to watch for and what a dentist looks for to confirm a diagnosis.

A slow heart rate is sometimes perfectly healthy, but it can also signal an underlying issue. Learn what causes it and when to see a doctor.

Practical tips to help your baby sleep safely on their back, from swaddling techniques to setting up a sleep-friendly environment.

Night wakings at 10 months often come down to sleep regressions, separation anxiety, teething, or nap timing. Here's how to figure out what's going on.