From the Office of Research on Women’s Health
Puberty is the set of physical changes that occur when a person becomes sexually mature. Puberty usually occurs between ages 10 and 14 for girls and ages 12 and 16 for boys.
In girls, the first sign of puberty is often breast development. Other signs are the growth of hair in the pubic area and in the armpits. Sometimes acne appears and, eventually, menstruation begins.
In boys, puberty usually begins with the testicles and penis getting bigger, then hair grows in the pubic area and armpits. Muscles grow, the voice deepens, and acne and facial hair develop as puberty continues.
Along with these changes, both boys and girls usually have a growth spurt (a relatively rapid increase in height) that lasts for about 2 or 3 years.
Menstruation, also called a period or menstrual period, is the part of a woman’s monthly cycle in which blood and tissue are discharged from the vagina. Most menstrual periods last from 3 to 5 days.
Girls can start menstruating between the ages of 8 and 16 – in the United States, most girls start menstruating at about age 12. The menstrual cycle is the process by which a woman’s body prepares for a possible pregnancy each month.
The average menstrual cycle is 28 days from the start of one to the start of the next, but it can range from 21 days to 35 days.
For some women, their menstrual cycle may not occur monthly and, when it does occur, it is likely to be longer or shorter than 28 days. Each woman needs to be aware of her own cycle.
Premenstrual symptoms (PMS)
It is important to tell your health care provider if you have severe cramping and pain or other symptoms before or during menstruation. Severe premenstrual symptoms may be premenstrual dysphoric disorder (PMDD). Talk to your health care provider if your premenstrual symptoms are severe enough to interfere with your daily activities.
Some women have other symptoms around the time of menstruation, including cramping, bloating, sore breasts, food cravings, mood swings, irritability, headache, and fatigue.
If a period is occasionally painful, placing a heating pad on the abdomen and using over-the-counter pain relievers may help lessen discomfort.
for more information: www.nichd.nih.gov