One of the most famous symptoms of premenstrual syndrome is being in a bad mood, despite seeming somewhat subjective, it really has a scientific explanation. Luckily for us (and for those next to us) it does not affect all women in the same way or to the same intensity. The basis of all the changes in our personality on those days are the hormones and the change in their levels.
Progesterone, a female hormone, begins to increase in our body in the ovulatory phase, around day 14 of the menstrual cycle. Its function is to make the endometrium stronger and thicker since it is there where the fertilized egg will develop. If said fertilization does not occur, progesterone levels decrease, so the endometrium loses strength and is shed, thus producing menstrual bleeding.
The Central Nervous System
- In the central nervous system is the hypothalamus, responsible for regulating emotions among other things. Inside the hypothalamus are GABA receptors, a type of receptor on neurons. These also have what are called modulators, which make it easier for GABA receptors to bind with their neurotransmitter. Progesterone is one of those modulators, and being at high levels, they make their work difficult.
- In the last phase of the menstrual cycle, progesterone levels decrease, which is why they release GABA receptors and begin to inhibit neurons related to feelings and mood changes. This is the reason why many women are more irritable on the days close to menstruation.