The thyroid gland is involved in growth, body temperature, and metabolism. About 2 million Americans have thyroid-related diseases. PMS-related symptoms are mainly related to hypothyroidism. Symptoms of hypothyroidism include fatigue, weight gain, irregular menstrual cycles, lower body temperature, hair loss, and dry skin. These symptoms are similar to PMS symptoms, and in particular, symptoms caused by a low body temperature appear to have a lot to do with PMS.
Symptoms caused by a low body temperature may include fatigue, loss of concentration, anxiety, depression, headache, and fluid retention. Female hormones are also related to body temperature. The progesterone level drops right before the menstruation period, resulting in a decrease in body temperature, which is also believed to be linked to the function of the thyroid gland.