What is PMS?

Premenstrual syndrome (PMS) is the term used to describe the physical and emotional changes that occur each month in women, approximately one week before menstruation.

What causes PMS?

Although experts are unsure of the exact etiology of premenstrual syndrome, they believe that hormonal changes that take place during the second part of the menstrual cycle are a possible contributing factor.

About halfway through the cycle, ovulation occurs, so the body releases an egg at that time, which reduces estrogen and progesterone levels. A change in these hormone levels can cause both physical and emotional problems.

Serotonin levels are also affected by variations in estrogen and progesterone levels. This neurotransmitter helps control mood, sleep patterns, and hunger. Low serotonin levels are associated with PMS symptoms such as moodiness and irritability, as well as sleep difficulties and strange food cravings. One of the most frequent and severe symptoms of PMS is mood swings.


Typically, PMS symptoms begin a few days before bleeding starts and end during your period.

Some symptoms are:

  • Bloating, swollen ankles, and acne.
  • Clumsiness or poor coordination.
  • Food cravings and weight gain.
  • Diarrhea and/or indigestion. 

Also, you may feel discomfort throughout your body, such as back pain, swelling, breast pain, headaches, migraines, and abdominal pain.

In addition, you may notice that you are more agitated, anxious, or depressed, and you may have trouble falling asleep and experience mood swings.