Premenstrual Syndrome (PMS)

What Is It?

Premenstrual syndrome (PMS) is a collection of symptoms that many women experience during the one to two weeks before a menstrual period. These symptoms may be physical, psychological and emotional. They disappear soon after the start of menstrual bleeding.

Researchers are not certain what causes PMS. The most popular explanation is that PMS symptoms are related to cyclic changes in:

  • Female sex hormones

  • Pituitary hormones

  • Prostaglandins

  • Certain brain chemicals (neurotransmitters)

There is some evidence that magnesium deficiency could play a role.

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