1. Health

Questions and Answers About Periods and the Menstrual Cycle for Teens

What is a Menstrual Cycle?


Updated May 19, 2014

The menstrual cycle is how a woman's body prepares for the possibility of pregnancy each month. Your menstrual period is just one part of this cycle. A cycle's length is determined by counting from the first day of one period to the first day of the next period. The average menstrual cycle is 28 days long. However, a cycle can range anywhere from 23 days to 35 days.

What Happens During the Menstrual Cycle?

During the menstrual cycle, an egg is released from the ovaries. While the egg is traveling down the fallopian tubes and towards the uterus, the uterus is building up a lining that consists of extra blood and tissue. The lining of the uterus will thicken and, if pregnancy occurs, blood vessels in the lining will enlarge to nourish the growing fetus. If the egg becomes fertilized by a sperm cell, the egg will attach itself to the uterine wall and a fetus will begin to develop. If the egg goes unfertilized, the thick lining that builds up during the menstrual cycle is not needed and is shed during your period. The unfertilized egg either dissolves or is absorbed into the body. After the period ends, a new menstrual cycle begins.

What is A Period?

A period is a part of the menstrual cycle when the thick uterine lining and extra blood are shed through the vaginal canal. Periods can be light, moderate, or heavy, and the menstrual blood that is shed can range from a few tablespoons to a 1/2 cup per period. This can vary from girl to girl, and it can vary from period to period for the same girl. Many girls experience a light flow for the first day or two, then a heavier flow, followed by another light day. Some girls have a heavy flow on the first day. For the first few years after you start menstruating, your period may be very irregular. How old is a girl when she gets her first period? In the United States, the average age a girl starts menstruating is 12. However, this does not mean that all girls start at the same age. A girl can begin menstruating anytime between the ages of 8 and 16. Menstruation will not occur until all parts of a girl's reproductive system have matured and are working together. This time in a young womans life is called "puberty."

How Long Should My Period Last?

Because all girls are different, menstrual periods can vary from girl to girl. One girl might have a 3-day period and another girl might have a 7-day period. It might take several years for a girl's period to become regular. One month the period might last 4 days, whereas the next month it might be 6 days. Some women experience irregular periods for several years and might not ever be "regular." Some doctors will prescribe birth control pills to help regulate your menstrual cycle. Talk to your doctor to find how you can regulate your cycle if it is irregular.

When Should I Change My Pads or Tampons During My Period?

Sanitary napkins (pads) should be changed as often as necessary, before the pad is soaked with menstrual flow. Each woman decides for herself what is comfortable. Tampons should be changed every 4 hours. Make sure that you use the lowest absorbency of tampon available. For example, do not use super absorbency on the lightest day of your period. This can put you at risk for Toxic Shock Syndrome (TSS). TSS is a rare but potentially deadly disease. The risk of TSS can be lessened or avoided by not using tampons, or by alternating between tampons and pads during your period. If you experience any of the following symptoms while you are menstruating and using tampons, you should contact your doctor immediately:
  • Sudden, unexplained, high fever
  • Muscle aches
  • Diarrhea
  • Dizziness and/or fainting
  • Sunburn-like rash
  • Sore throat
  • Bloodshot eyes

Does Having My Period Mean I Can't Have Any Fun?

Absolutely not! Your period should not affect your daily activities. You can continue to exercise, swim, bike ride, and have fun. Some girls and women even find that exercising while they are having their menstrual period reduces or prevents stomach cramps and discomfort.
  1. About.com
  2. Health
  3. Women's Health
  4. Teen Health
  5. Answers to Your Questions About First Periods

©2014 About.com. All rights reserved.

We comply with the HONcode standard
for trustworthy health
information: verify here.