A girl's first menstrual period typically occurs between the ages of 9 and 15, according to Boston Children's Hospital's Center for Young Women's Health. At this time, the ovaries begin to produce hormones to stimulate breast development and the menstrual cycle. It is not uncommon for teenagers to have irregular periods until their bodies are able to balance out the hormonal changes, which typically takes from one to three years, states TeensHealth.
What is a Period?
Every month, the pituitary gland releases follicle-stimulating hormone and luteinizing hormone. The FSH stimulates the growth of the follicle in the ovary, while LH is responsible for causing the body to ovulate, according to the Mayo Clinic. The egg travels down the fallopian tube into the uterus to be fertilized. If fertilization does not occur, the body sheds the uterine lining. This blood exits the body through the vagina, and it is what the menstrual period you get is.
Menstrual cycles may be a bit different from teen to teen. The average length of the menstrual cycle is 28 days from the first day of one period to the first day of the next period, but your cycle may be as short as 21 days or as long as 35 days, says Boston Children's Hospital's Center for Young Women's Health. The length of time that you bleed can be anywhere from three to seven days, and it can be light, heavy or a combination of the two.
At the beginning of menstruation, irregular periods are normal, as the body adjusts to changes that occur after a girl's first period, and over time, the periods fall into a predictable cycle. Weight loss, stress, too much exercise or an eating disorder may cause menstrual irregularities, but irregular periods can also occur in teens who haven't had any major life disruptions. It's also common for teen girls to skip a period during the first few years, or due to high levels of stress. According to PubMed Health, some conditions, such as polycystic ovary syndrome, which causes an imbalance of the female sex hormones in the body, can also cause irregular periods.
Cramping and Side Effects
Blood flow isn't the only thing that comes with a menstrual cycle. These hormonal changes, commonly known as premenstrual syndrome, may affect emotions and may cause irritability in some teens. Cramping is also common, as the uterus contracts to help release the blood. Dr. Sharon Bergquist, from the Emory School of Medicine in Atlanta, advises taking over-the-counter, anti-inflammatory medications such as ibuprofen or naproxen, if the cramps become too painful. Placing a heating pad on the area may also help relieve pain.
- Boston Children's Hospital's Center for Young Women's Health: Menstrual Periods
- TeensHealth: A Normal Period Doesn't Have to Be Regular
- WebMD: Understanding Your Period and Menstrual Cycle
- Mayo Clinic: Follicle Stimulating Hormone and Luteinizing Hormone (Intramuscular Route, Subcutaneous Route)
- PubMed Health: Polycystic Ovary Syndrome
- David De Lossy/Photodisc/Getty Images