How Do Hormonal Changes Cause PMS?
The exact cause of PMS is still not known, but researchers believe that PMS symptoms occur because progesterone and estrogen cause changes in brain chemicals called neurotransmitters. The most likely neurotransmitters affected are: • Serotonin: Women with PMS have fluctuations in serotonin levels. These changes may cause depression and carbohydrate cravings. Serotonin is made by the body from the amino acid tryptophan. • GABA: GABA stands for gamma-aminobutyric acid. This neurotransmitter is important in feeling calm. • Endorphins: Endorphins are important in the experience of pain and pleasure. Estrogen and progesterone change endorphin levels. • Norepinephrine: Norepinephrine and epinephrine are also neurotransmitters that influence mood. In addition, these substances play a role in blood pressure and heart rate.
