Menstruation, absent
Alternative names:
missed periods; lack of menses; periods, missed; amenorrhea
Definition:
The absence of menstrual flow, either primary (menstruation
fails to begin before age 16) or secondary (menstruation begins
at the appropriate age but later ceases for 6 or more months
in the absence of normal causes such as pregnancy,
lactation or menopause).
Considerations:
Many perfectly normal females begin to menstruate later
than most (the average age is 12 to 14 years).
Pregnancy is often the
first thought when a period is missed, but there are many
reasons for having a late period.
The incidence of primary
amenorrhea in the U.S. is only 2.5%. The incidence of
secondary amenorrhea
(due to some cause other than pregnancy) is about 4% in the
general population.
Increased risk is associated with extreme and prolonged exercise
(particularly without adequate conditioning), body fat content
less than 15 to 17%, extreme
obesity, and taking hormonal supplements.
Symptoms associated with amenorrhea may include headache,
galactorrhea (breasts
produce milk in woman who is not pregnant
or breast feeding an infant), visual
loss (in rare cases of pituitary tumor), marked weight
gain or weight loss,
dry vagina, increased
hair growth in a "male" pattern (hirsutism),
voice changes, and breast size changes.
Common causes:
PRIMARY AMENORRHEA
SECONDARY AMENORRHEA
Note: There may be other causes of amenorrhea. This list
is not all inclusive, and the causes are not presented in
order of likelihood. Amenorrhea can be caused by unlikely
diseases and medications. The causes also may vary based on
a woman's age, as well as on the specific characteristics
of the symptom.
Update Date: 02/09/00
Updated by: J. Gordon Lambert, MD, Associate Medical Director,
Utah Health Informatics and adam.com
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