What is premenstrual syndrome (PMS)?
Premenstrual syndrome (PMS) is a group of physical, emotional and behavioral symptoms that commonly occur in the two weeks prior to menstruation.

What is PMDD?
Some women experience premenstrual symptoms so severe that they interfere with daily activities. These women have a condition called premenstrual dysphoric disorder (PMDD), which is diagnosed under specific criteria established by medical authorities. While the symptoms are similar, PMDD is considered a separate disorder from PMS.

What are some common symptoms of PMS?
There are more than 150 symptoms attributed to PMS, but most fall into one of two categories, physical or emotional/behavioral. Some of the most common physical symptoms are abdominal cramps, breast swelling, breast tenderness, fatigue and bloating. Some of the most common emotional/behavioral symptoms are irritability, hostility, aggressive behavior, anxiety and depression.

How common is PMS?
PMS is common among women of childbearing age. Most women experience some of the symptoms associated with PMS at some point in their lives, but not all women have the syndrome. Estimates of the exact percentage of women that have PMS vary widely. According to the National Institutes of Health, an estimated 75 percent of menstruating women experience some form of PMS.

What causes PMS?
The exact cause of PMS is unknown, although there are several factors that appear to contribute to its occurrence. Some women are particularly sensitive to the normal fluctuations of hormone production during the menstrual cycle, while others react to the changes in serotonin, a brain chemical that affects mood. Women with vitamin deficiencies and those who consume excessive salt, sugar, caffeine or alcohol may also experience PMS symptoms more frequently.

How is PMS diagnosed?
There are no tools or tests that can be used to conclusively diagnose PMS. Rather, doctors determine whether an underlying medical condition is causing symptoms. If a medical condition can't be found, then doctors recommend patients keep a menstrual diary to identify the type of symptoms experienced and track when they occur during the menstrual cycle. If symptoms occur in a predictable pattern in the two weeks before menstruation and then cease when menstruation begins, PMS is diagnosed.

How is PMS treated?
PMS is treated in a variety of ways. First, doctors might recommend lifestyle changes such as eating a well-balanced diet, taking vitamins, exercising and reducing stress. Both over-the-counter and prescription medications are used in patients with more severe symptoms.

Can PMS be prevented?
Because its cause is unknown, there is no known way to prevent PMS. However, making lifestyle changes can help prevent or reduce the severity of symptoms.