Amenorrhea (the Absence of Periods)
Girls who haven't started their periods by the time they're 15 years
old or 3 years after they've shown the first signs of puberty have
primary amenorrhea, which is usually caused by a genetic abnormality, a
hormone imbalance, or a problem with the way the reproductive organs
developed. Hormone imbalances also can lead to secondary amenorrhea, which is
when a girl who had normal periods suddenly stops menstruating for more
than 6 months or three of her usual cycles.
Since pregnancy is the most common cause of secondary amenorrhea, it
should always be ruled out when a girl skips periods. In addition to
hormone imbalances and pregnancy, other things that can cause both
primary and secondary amenorrhea include:
- stress
- significant weight loss or gain
- anorexia (amenorrhea can be a sign that a girl is losing too much weight and may have anorexia)
- stopping birth control pills
- thyroid conditions
- ovarian cysts
- other conditions that can affect hormone levels
Something else that can also cause primary and secondary amenorrhea is excessive exercising
(often distance running, ballet, figure skating or gymnastics) combined
with a poor diet, which usually results in inappropriate weight loss or
failure to gain weight during growth. But this doesn't include the usual gym class or school sports team,
even those that practice often. To exercise so much that she delays her
period, a girl would have to train vigorously for several hours a day,
most days of the week, and not get enough calories, vitamins, and
minerals.
Source: kidshealth