What is menstruation?

Dr. Jeanne Morrison, PhD
Family Practitioner

Menstruation, also called menstrual cycle or menses or a period, is the monthly vaginal bleeding a woman has. A woman who is not pregnant but who is in her childbearing years will shed the lining of her uterus each month. Puberty marks the beginning of menstruation and menopause is the permanent end. For most women, menstruation lasts for 3 days to a week.

A woman's menstrual period may be absent, irregular, abnormally heavy, or painful. Menstrual problems can range from mild to severe. For example, most women who menstruate have some degree of premenstrual syndrome (PMS), but this can range from mild breast tenderness or bloating to a debilitating form known as premenstrual dysphoric disorder (PMDD), marked by symptoms such as serious anger and depression. Another menstrual problem, polycystic ovary syndrome, is linked to hormone imbalances, obesity, infertility, diabetes, increased cancer risk and other serious complications.

Different menstrual problems have different causes. For example, researchers think PMS may be caused by variations in levels of hormones and other body chemicals, possibly worsened by underlying stress and depression. Amenorrhea (absent periods) can be caused by birth control pills, shots, implants, some medications, eating or exercise disorders, stress and a host of other factors; although in healthy, sexually active women, pregnancy is the most common reason why a period doesn't appear.

Dr. Jessica A. Shepherd, MD
OBGYN (Obstetrician & Gynecologist)

Menstruation is the process in women of monthly vaginal bleeding. Hormone imbalances are typically the cause of most menstrual problems, but fibroids and other conditions can also cause abnormal or heavy bleeding. Watch as OBGYN specialist Jessica Shepherd, MD, discusses the main causes of menstrual issues.

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.