Causes of Missed Period

Content provided by the Faculty of the Harvard Medical School

Causes of Missed Period

Question:

I am a 15-year-old girl and I have had my period since I was about 11. But now I am two months late. I have never been anywhere close to a guy, but my parents are convinced that I am pregnant and want me to go get checked out. I am terrified of doctors and want to prolong the appointment as long as possible. What could be wrong with me?

Answer:

Amenorrhea is the absence of periods in a girl or woman of reproductive age. Primary amenorrhea occurs if a girl reaches 16 years without a period but otherwise has normal breast and pubic hair development. If a girl starts regular cycles and then stops for at least three months, the term secondary amenorrhea is used to describe her condition.

An occasional skipped period is a very common occurrence and is not a cause for alarm. Menstruation will usually resume without treatment, so a little patience may spare you from a lot of testing.

There are many different causes of amenorrhea, which is a reflection of the underlying complexity of the female reproductive system. However, before doing a comprehensive evaluation, the possibility of pregnancy must always be considered in sexually active girls. The sooner a woman knows she is pregnant, the better, so checking a pregnancy test is usually at the top of the list when evaluating amenorrhea.

Once pregnancy is excluded, the causes of amenorrhea include:

• Problems in the lower genital tract including blockage of the vagina. This is more likely a cause of primary rather than secondary amenorrhea.

• Damage to the uterine lining, called Asherman's syndrome. It usually results from prior uterine surgery such as a dilation and curettage (D&C).

• Disorders of the ovary. Ovarian failure can result from genetic conditions and major medical problems. In general, it is an uncommon cause of amenorrhea in younger girls.

• Hormone dysfunctions of the pituitary gland. The pituitary gland is a small but important organ located in the brain. Pituitary disorders can cause your thyroid gland to be underactive and an elevation of the hormone prolactin, both of which can disrupt menstrual function.

• Hypothalamic amenorrhea. This category of causes of amenorrhea includes substantial weight loss or gain, stress, and extreme exercise. There are no tests to absolutely confirm that these relatively common events are the cause of amenorrhea in any given individual. Thus hypothalamic amenorrhea is usually diagnosed after a process of exclusion of other conditions.

So if you are not sexually active, do a home pregnancy test and show the results to your parents. Then, if you don't have other symptoms, it makes sense to wait one more month to see if your period comes. If you skip three periods in a row, you should call your doctor's office for advice. He or she will likely want to do a full exam, including a pelvic exam. I know you want to avoid that, but the exam is an important part of evaluating a woman's health.

Last updated:	March 03, 2009