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 women have symptoms before menstruating that are severe enough to be classified as premenstrual syndrome (PMS). Pain during menstruation (dysmenorrhea) includes menstrual cramps. They may be caused by hormone-like substances known as prostaglandins. Severe dysmenorrhea may also be a symptom of other conditions, including endometriosis or uterine fibroids. Most mild cramps can be treated with over-the-counter analgesic medication (painkillers) or with the use of heating pads or hot water bottles.

During menstruation, prolonged tampon use has been associated with an extremely rare infection called toxic shock syndrome (TSS). To avoid TSS, women 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 or gynecologist. Secondary amenorrhea refers to someone who has menstruated previously but has stopped. The most common reason to miss a period is pregnancy, but other causes of missed periods may include:

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

Irregular periods may indicate hormonal imbalances or such conditions as polycystic ovarian syndrome (PCOS). Women may also experience very heavy bleeding (menorrhagia) or vaginal bleeding between periods (metrorrhagia). These may be symptoms of some sexually transmitted diseases such as gonorrhea, uterine abnormalities such as cancer, polyps or fibroid tumors. Menorrhagia and metrorrhagia may be controlled by birth control pills in women who are able to use this type of medication.

Women should consult their gynecologist 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.