The exact cause of premenstrual syndrome (PMS) is not fully understood, but various possible factors may contribute to the symptoms.
These are described below.
Hormone changes
During your menstrual cycle, levels of hormones such as oestrogen and progesterone rise and fall. Hormone changes are thought to be the biggest contributing factor to many of the symptoms of PMS. The fact that PMS improves during pregnancy and after the menopause, when hormone levels are stable, supports this theory.
Chemical changes
Like your hormone levels, certain chemicals in your brain, such as serotonin, fluctuate during your menstrual cycle. Serotonin is known to help regulate your mood and make you feel happier, so it is possible that women with low levels of serotonin are particularly sensitive to the symptoms of PMS. Low levels of serotonin may also contribute to symptoms such as:
- tiredness
- food cravings
- insomnia (difficulty sleeping)
Lifestyle factors
Weight and exercise
Research has shown that you are more likely to have PMS if you are obese (with a body mass index of more than 30) and if you do little exercise.
Read more about calculating your BMI and health and fitness.
Stress
You may find that your symptoms of PMS get worse as you become more stressed. While it is not a direct cause, stress can aggravate the symptoms of PMS.
Read more about how to manage stress.
Diet
Eating too much of some foods and too little of others may also contribute to PMS symptoms. For example, too much salty food may add to fluid retention and make you feel bloated. Alcohol and caffeinated drinks can disrupt your mood and energy levels. Low levels of vitamins and minerals may also make your PMS symptoms worse.
Read more about maintaining a balanced diet.
