What causes premenstrual syndrome (PMS)?
No one really knows what causes premenstrual syndrome. PMS remains an enigma because of the wide-ranging symptoms and the difficulty in making a firm diagnosis. Several theories have been advanced to explain the cause of premenstrual syndrome. Research suggests premenstrual syndrome is probably due to hormonal changes that occur before each period. It isn't clear why some women have symptoms that have a major effect on their lives while other women don't.
The most popular explanation for premenstrual syndrome is that these symptoms are related to cyclic changes in female sex hormones, pituitary hormones, prostaglandins and certain brain chemicals known as neurotransmitters. While it seemed logical to many that the reproductive hormones involved in the menstrual cycle were the cause of premenstrual syndrome, research has proven that there are no differences in estrogen, progesterone,FSH, LH, prolactin, and testosterone levels between women with and without premenstrual syndrome. This only confirms that ovulation acts as the "trigger" but is not in itself the cause. In the past, progesterone supplementation was supported as a treatment for premenstrual syndrome, but has been proven to be ineffective. As discussed in treatments, the only hormonal therapy that works is a regimen that prevents ovulation from occuring. Some researchers have suggested that premenstrual syndrome may be related to abnormally low blood sugar (hypoglycemia), abnormally low levels of thyroid hormones (hypothyroidism) or a diet low in B vitamins, calcium or magnesium. However, recent studies do not support these theories. Preliminary studies indicate that magnesium deficiency could play a role.
Endorphins are opium-like chemicals manufactured by the body. Opium-like chemicals, including endorphins, are involved in the sensation of euphoria and the perception of pain. Thus, some have proposed that premenstrual syndrome is a state of endorphin deficiency. Endorphin levels in the blood do fluctuate. However, these levels are not felt to reflect the activity of endorphins in the brain. Therefore, there is not enough evidence to support this theory.
It is believed that lifestyle may play a significant role in premenstrual syndrome. This is because premenstrual syndrome symptoms appear to be most troubling in women who smoke, lead stressful lives, rarely exercise, sleep too little or whose diet is high in caffeine, alcohol, salt, red meat or sugary foods such as chocolate or candy. However, it's not clear whether these factors increase your risk of premenstrual syndrome or if premenstrual syndrome accounts for these differences in lifestyle. For example, studies looking at the influence of stress do not find a relationship between stress and the severity of premenstrual syndrome. It is more likely that premenstrual syndrome causes stress rather than that stress causes premenstrual syndrome.
It's possible that medications may exaggerate the symptoms of premenstrual syndrome. Oral contraceptives (birth control pills) have been known to produce symptoms of premenstrual syndrome in some women. However, some women have noticed that their symptoms improve or disappear while using birth control pills.
Another theory explaining premenstrual syndrome involves inflammatory substances called prostaglandins. Prostaglandins are produced in the areas where premenstrual syndrome symptoms originate, namely, breast, brain, reproductive tract, kidney, and gastrointestinal tract. This suggests they may play a role in problems such as cramping, breast tenderness, and gas, diarrhea, and constipation.
In recent years, there has been some controversy in the medical community about the difference between premenstrual discomfort and true premenstrual syndrome. This is because premenstrual discomfort is fairly common among women of childbearing age, affecting about 75 percent of all menstruating women. However, only about 3 percent to 8 percent of women have symptoms that are severe enough to either disrupt their personal relationships or interfere with their normal work and home responsibilities. Some doctors feel that only these women — the small percentage with severe symptoms — are the ones who suffer from true premenstrual syndrome. These doctors regard premenstrual syndrome as a severe illness that is equivalent to what psychiatrists call premenstrual dysphoric disorder (PMDD). However, other doctors use a less stringent definition for premenstrual syndrome, which includes mild to moderate symptoms.