What happens in a woman's body during PMS and menstruation? Premenstrual syndrome (PMS) is a set of physical and psychological symptoms that usually appear 1-2 weeks before menstruation and disappear with the onset of menstruation. It is estimated that PMS regularly affects approximately 80% of menstruating women, with symptoms and their intensity varying greatly from individual to individual¹. PMS is primarily caused by fluctuations in female hormones (estrogen and progesterone) in the second half of the menstrual cycle, which affect the production of neurotransmitters such as serotonin, leading to fluctuations in mood, emotions and energy². PMS care can be found here . What are the most common symptoms of PMS? Psychological symptoms: Sudden mood swings, irritability, anxiety Increased sensitivity, crying,...