The word “Functional,” here in quotes, means that there is no outside disease causing the condition, in this case, cessation of menstrual periods, i.e. Amenorrhea. So even though the symptom is present, the woman is able to function; life goes on. Lots of organs have “functional” symptoms. Usually we don’t know what causes them, although we do understand what a person is experiencing.
In this case, Amenorrhea is due to dysfunction of the Hypothalamus, the part of the brain which begins the complex series of hormone production leading to the menstrual period (see Ovulation). The dysfunction is not due to a tumor or disease, but rather an inconsistency in the amount of energy required for activities, and the amount that’s available. This interferes with the Hypothalamus’s ability to communicate with the Pituitary Gland, so in the end, the ovaries are never signaled to produce estrogen. . We don’t know the exact mechanisms, but it likely has to do with Cortisol, one of our stress hormones produced by the Adrenal Glands.
A variety of situations can result in too much energy being used, or not enough nutrition to support it. These include:
- Eating disorders
- Nutritional deficiencies (malnutrition, fad diets, etc.)
- Excessive exercise, especially activities cultivating low body weight like running, ballet dancing, gymnastics, figure skating
- Stress (severe): physical or psychological
- Sometimes, no obvious factor can be pinpointed.
The ovaries of women with Functional Amenorrhea (also called Hypothalamic Amenorrhea) don’t produce enough estrogen. This can lead to a variety of other manifestations or symptoms, including decreased breast size, vaginal dryness (causing painful sexual intercourse), and difficulty or inability to conceive. They don’t tend to have hot flashes which would suggest another diagnosis (Premature Menopause). The most serious complication is bone loss, leading to an increased risk of fractures, especially stress fractures (tiny, almost microscopic ones, that don’t cause bone to split apart (at least at first), and are quite painful. It’s uncertain whether women with Functional Amenorrhea have more risk of heart disease. They have been shown to suffer more Anxiety and Depression.
We may want to confirm our diagnosis by treating with 10 days of progesterone pills, or a month of birth control pills (with its one week without hormones; iron tablets or dummy pills instead). If that results in a menstrual period, our diagnosis is correct.
Functional Amenorrhea is essentially a diagnosis of exclusion, meaning no other cause has been found for cessation of menstrual periods. See our topic Amenorrhea which describes the diagnostic work-up.