Health Topics for Teenage Concerns

Child and Adolescent Program

Growing Up Female

Most girls start growing taller and heavier at about age 12.  They continue to grow at a fast rate for about 2 years and then slow down.  Some girls think growing so quickly between the ages of 12 and 14 is a problem because boys their age are usually smaller and lighter than they are during this time.  Most boys don't start growing in height and weight until they are around 14, about 2 years after most girls start.  However, once the boys start, they keep growing and pass up most of the girls.

When a girl starts to mature physically, the shape of her body begins to change.  Her hips will become wider and curvier.  A definite waistline will start to appear.  Her arms and legs will fill out and become rounder looking.  Breasts will develop.  Some girls are especially concerned about the size of their breasts.  They become self-conscious if they have breasts before their friends do, or if they are still flat-chested when other girls are filling out.  Every girl's rate of growth is different. 

Another sign a girl's body begins to mature physically and sexually is the gradual appearance of pubic, facial, underarm, and leg hair.  This is a normal and natural sign that a girl's body is growing up.

Chemical substances the body produces, called hormones, control all of these changes.  These hormones control the growth and changes in your body by telling it what to do and when to do it.

Skin health is a major concern to many teens because acne, blackheads, whiteheads, and pimples begin to appear on the face.  Skin and hair can get oily very quickly.  The body's hormones and bacteria on the skin also influence these changes.

Another important change occurs when a girl begins her period, which is called menstruation.  Menstruation is the periodic discharge of blood and tissue from the nonpregnant uterus through the vagina.  The uterus is also known as the womb.  Menstruation may last an average of 4 to 5 days at 4-week intervals.  When a girl's body finally develops menstrual cycles, the girl is capable of getting pregnant.

Menstruation occurs when the pituitary gland located at the base of the brain releases a hormone that causes changes to the reproductive organs.  The ovaries release an egg cell and the lining of the womb thickens with blood and other liquids.  If the egg cell is united with a male sperm cell during sexual intercourse, then the fertilized egg cell will grow into a baby inside the womb.  If the egg is not fertilized, meaning not united with a sperm cell, there is no need for the thickened lining.  So, the girl's period (menstrual blood flow) begins.

Some girls begin their periods as early as age 9 and others as late as age 18.  This is perfectly normal.  A good indication of the age a girl may begin her period is the ages of her sisters and mother when their first menstrual period began.  The age at which a girl starts menstruating is not related to her femininity or womanhood.

The maturing process of the body is a normal, natural process.  There is nothing to be worried or ashamed about.  Every girl goes through natural physical and emotional changes on her way to becoming a woman.

Any girl with questions or concerns about the changes and development of her body should talk to someone she feels comfortable with, such as her parents, a teacher, school nurse, counselor, or healthcare provider.

Disclaimer:  This content is reviewed periodically and is subject to change as new health information becomes available.  The information provided is intended to be informative and educational and is not a replacement for professional medical evaluation, advice, diagnosis or treatment by a healthcare professional.