Menstruation can cause problems ranging from mild discomfort to pain. Some body changes during the monthly cycle are normal, including breast tenderness or some discomfort just before menstruation.

Some girls have physical and emotional symptoms before menstruating that are severe enough to be classified as premenstrual syndrome (PMS). Symptoms associated with PMS include:

• Acne
• Backaches
• Bloating
• Sore breasts
• Digestive problems (e.g., constipation, diarrhea)
• Depression
• Difficulty concentrating
• Difficulty handling stress
• Fatigue
• Food cravings
• Headaches
• Irritability

PMS is believed to be the result of changes in a girl’s hormone levels. It usually is most severe about a week before a girl’s menstrual cycle begins and ends once a period starts. In most cases, PMS does not appear until several years after a girl’s menstrual cycle begins.

Discomfort may also be present during menstruation. Girls often experience cramps during menstruation. These cramps tend to affect the lower abdomen, but they may also affect the back or the thighs. Cramps may be caused by hormone-like substances known as prostaglandins that cause the muscles of the uterus to contract. In most cases, cramps last for only a day or two. They may be dull and achy, or sharp and intense. As girls get older, cramps often become less common.

Pain during menstruation is called dysmenorrhea. However, physicians generally use the term to refer to severe menstrual pain. There are two types:

• Primary dysmenorrhea. More common in teens, it is the result of large amounts of prostaglandins rather than disease or another condition. It leads to nausea and vomiting, headaches, backaches, diarrhea and severe cramps. Symptoms tend to last for just a day or two.
  
  
• Secondary dysmenorrhea. Result of pain from gynecologic conditions such as polyps, endometriosis (tissue normally found only inside the uterus grows elsewhere), pelvic inflammatory disease (PID) and adenomyosis (uterine tissue that grows into the muscular wall of the uterus).

Girls who have particularly painful or long periods (such as those that last more than 10 days) are urged to consult a physician, such as a gynecologist (physician who specializes in the female reproductive system).  

During menstruation, prolonged tampon use has been associated with an extremely rare infection called toxic shock syndrome (TSS). To avoid TSS, girls should follow the tampon package instructions, change their tampons frequently and use the lowest absorbency tampon possible for their menstrual flow.

Amenorrhea is the lack of menstruation. Primary amenorrhea refers to girls who have not experienced their first periods. A girl who has not had her first period by age 16 should consult her physician. Secondary amenorrhea refers to someone who has menstruated previously, but has stopped. The most common reason to miss a period, once the menstrual cycle has become regular for the individual girl, is pregnancy. Girls who have gone six months without a period should see a physician. In addition, any girl who is sexually active is urged to see a physician if she misses even one menstrual period.

Other causes of missed periods may include:

• Breastfeeding
• Stopping the use of birth control pills
• Extreme weight loss
• Excessive exercise (e.g., ballet dancers, distance runners, gymnasts)
• Stress
• Hormonal imbalances

Irregular periods may indicate hormonal imbalances or such conditions as polycystic ovarian syndrome (PCOS).

Girls may also experience very heavy bleeding (menorrhagia), most often due to an imbalance between levels of estrogen and progesterone in the body that allows the endometrium to build up excessively before it is shed. This condition is fairly common in girls, because many adolescents have slight hormone imbalances during puberty. Girls who have menorrhagia may soak through at least one sanitary napkin an hour for several hours in a row, or may have periods that last longer than one week. Girls who have menorrhagia may begin to withdraw socially as they become afraid of an inability to control bleeding in public situations.

Some girls experience vaginal bleeding between periods (metrorrhagia). This may be a symptom of some sexually transmitted diseases, uterine abnormalities such as cancer, polyps or uterine fibroids. Other potential sources of menorrhagia or metrorrhagia include:

• Stress
  
• PCOS (a hormonal disorder in which excessive amounts of androgens [male hormones such as testosterone] are produced by the ovaries)
  
• Birth control pills with inadequate doses of hormones for the patient
  
• Trauma to the cervix, vagina or vulva
  
• Clotting disorders
  
• Inflammation or infection of the vagina or cervix
  
• Thyroid conditions

Menorrhagia and metrorrhagia may be controlled by using birth control pills.

Girls should consult their physician about any menstrual conditions that change quickly or become progressively worse. Missed or irregular periods or abnormal vaginal bleeding also indicate a need for medical consultation.

In diagnosing menstrual problems, the physician will perform a complete physical examination and compile a thorough medical history. Other procedures that may be used include a pelvic exam, a Pap smear (a procedure that collects cells from the cervix), blood tests to check hormone levels, and urine or stool tests.