Causes of Amenorrhea
Amenorrhea is not a condition or disease in itself; rather it is a symptom which may occur as a result of many other conditions. There are two classes of amenorrhea: primary and secondary. In primary amenorrhea, the woman with the condition has not had a menstrual period by the age of 16. In secondary amenorrhea, she has stopped menstruating after previously having had periods.
The most common reason for amenorrhea to occur is pregnancy, but there are many other causes, including medications, stress, low body weight or low body fat, hormonal imbalances, and scarring of the uterus or fallopian tubes. Some of these factors can prevent normal hypothalamus production, which may lead to amenorrhea.
The hypothalamus is a small area in the brain that produces several hormones, one of which is involved in stimulating ovulation and other events in the menstrual cycle. In hypothalamic amenorrhea, the hypothalamus does not produce gonadotropin-releasing hormone, which results in cessation of ovulation and menstruation.
In the long term, hypothalamic amenorrhea can lead to reduced estrogen production, which may put a woman at increased risk for heart disease and osteoporosis.
Diagnosis and Treatment for Hypothalamic Amenorrhea
Diagnosis of amenorrhea caused by hypothalamus dysfunction is often a process of elimination that might involve a lengthy series of tests. These can include a CT scan, x-ray, ultrasound, or MRI scan, and hormonal studies that test levels of hormones involved in ovulation and menstruation.
Amenorrhea due to hypothalamus dysfunction is most often caused by physical factors, but sometimes psychological factors such as stress are involved. When the cause of the condition is a factor such as excessive exercise, low body weight, or stress, it may be reversed by modifying the lifestyle to reduce the impact of such factors on the body. In some cases, hormone therapy may be able to stimulate hypothalamus production of needed hormones.
Occasionally, the condition may be caused by the presence of a tumor in the hypothalamus. In these cases the only effective treatment is often removal of the tumor, either with surgery or with radiation therapy or chemotherapy.
Advanced Fertility Center of Chicago: Secondary Amenorrhea
National Institute of Health MedlinePlus: Primary Amenorrhea
The Mayo Clinic: Amenorrhea
Vaishali Popat, MD, MPH for eMedicine.com: Primary Amenorrhea