ScienceInsights

Most 3-year-olds need 10–13 hours of sleep a night. Learn how to set the right bedtime and spot signs your toddler isn't getting enough rest.

Premenopause and perimenopause are often used interchangeably, but they mean different things. Here's what each term actually refers to and how to tell them apart.

Asthma cough needs specific treatment. Learn which inhalers, pills, and therapies actually work—and why standard cough medicine usually misses the mark.

Periods lasting more than 7 days may signal an underlying issue. Learn what causes long periods and when it's time to talk to a doctor.

Learn how facial melanoma can appear as flat patches, raised bumps, or even light-colored spots, and how to tell them apart from harmless age spots.

Daily vitamin D needs vary by person, but knowing the safe upper limits and toxicity risks helps you find the right dose for your situation.

Flu B typically clears in 5–7 days, but cough and fatigue can linger. Here's what to expect and when to be concerned.

Hives can appear within minutes or take hours, depending on the trigger. Learn how timing varies for food, medications, insect stings, and more.

Lifestyle changes like exercise, the DASH diet, and stress management can meaningfully lower diastolic blood pressure without medication.

For a 5'9" man, a healthy weight goes beyond the scale. Learn how BMI, body fat, and waist size work together to give you a clearer picture.