A female’s first menstrual period, known as menarche, occurs during puberty. Menstruation indicates that the body is mature enough for reproduction. About 98% of girls begin their periods by age 15.

A first menstrual cycle usually occurs between the ages of 10 and 16 with the average age of a first period being 12.4 years old. That’s a pretty wide range, so how do you know when your kid needs ...

Your period could be crampin’ your style — and your future health. Girls are reaching puberty faster than previous generations, a phenomenon perplexing researchers. The average age of the start of ...

Girls in the U.S. are getting their first menstrual period about 6 months earlier on average than they did in the 1950s and '60s. And more girls are beginning menstruation before the age of 9, which ...

One week you’re convinced your period’s coming, and then something feels off. The timing’s strange, so you start to wonder: ...