Medically reviewed by Cordelia Nwankwo, MD Key Takeaways Breast development usually starts about two years before the first period. Emotional changes and mood swings can occur just before the period.

Menstruation is a natural biological process experienced by nearly half the global population. Yet, for many girls, the first period arrives as a surprise—often misunderstood, feared, or even ...

A concerning new study conducted by Dr. Shruthi Mahalingaiah of the Harvard T.H. Chan School of Public Health has supported the claim that American girls are getting their periods earlier in life. The ...

There is unexpectedly large variation in height growth in girls after their first period. Every second girl grows either more or less in length than the 6–8 centimeters that is considered standard.

The most common reason behind painful periods in adolescents is primary dysmenorrhea. This occurs due to the release of prostaglandins, hormone-like chemicals that cause the uterus to contract during ...

Girls who grow up eating a healthier diet than their peers may be less likely to get their first menstrual periods at an earlier age — regardless of height or body mass index — a new study suggests.

Anna Lee Beyer writes about mental health, relationships, parenting, and books for Huffington Post, Romper, Slate, Glamour, Parents, and others. A first menstrual cycle usually occurs between the ages ...

Girls are getting their periods earlier and it is taking longer for their menstrual cycles to regulate – trends that are putting more girls at risk of health problems later in life. The average age of ...

There is unexpectedly large variation in height growth in girls after their first period. Every second girl grows either more or less in length than the 6-8 centimeters that is considered standard.