No one really knows what causes premenstrual syndrome (PMS), but there are lots of individual elements that come into play with the condition. The most elemental factor behind PMS is probably the normal fluctuations of the hormones in the days just before menstruation. The corollary to this theory is that PMS doesn't affect pregnant or menopausal women.
Some believe that certain other chemicals also fluctuate according to a woman's cycle and that this plays a role in triggering the signs and symptoms of PMS. Changing levels of serotonin, a chemical in the brain, may be one culprit since it is known that this neurotransmitter plays an elemental role in mood status. A decrease in serotonin could be a potential trigger for symptoms such as depression, insomnia, food cravings, as well as the fatigue that may come with PMS.
Sometimes a woman may suffer from a preexisting mental health ailment, such as depression. Often, women with intense premenstrual syndrome have been found to have clinical depression. Too much stress can make symptoms worse, but doesn't cause PMS.
Certain symptoms of PMS have also been linked to an excess or deficiency of certain minerals and vitamins. Salty foods, for example, can exacerbate the bloating while too much alcohol or caffeine can affect energy and mood. If you find that making basic changes in your lifestyle don't really mitigate your PMS symptoms, and there is a drastic impairment in your physical or emotional wellbeing, it's important to see your physician and seek advice on how to manage your condition.
There aren't any lab tests or anything physical your doctor can point to in trying to diagnose PMS. The most reliable finding is the predictable recurrence of the same symptoms at the same point in your cycle every month. Your doctor may ask you to record your symptoms on a calendar for two months in order to establish a pattern that suggests PMS. You will want to record both the day the symptoms began as well as the day they stopped. A record of when your menstrual period began and ended will also be helpful in pinpointing the cause of your symptoms. An alternative method is sometimes used in which the patient is given a questionnaire relating to symptoms experienced during the last two weeks of the cycle on through to the first day of the next menstrual period.