Menstruation, or a menstrual period, refers to the monthly process in which the uterus sheds blood and tissue in preparation for pregnancy.
Not having or missing a menstrual period is called amenorrhea. This condition is divided into two types:
Primary amenorrhea—when an adolescent female has not yet begun menstruation by around age 16 years
- Most females begin menstruating between the ages 9-18, but age 12 is the average.
- Secondary amenorrhea—when a woman who has previously menstruated misses three or more periods in a row
Copyright © Nucleus Medical Media, Inc.
Last reviewedSeptember 2012by Andrea Chisholm
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.