Causes of Amenorrhea - Absence of Menstrual Periods
Written by Kimberly Vaughn, MD
Sunday, 04 October 2009
A woman who has amenorrhea has either never had a menstrual period or has stopped having periods.
What is going on in the body?
There are two categories of amenorrhea:
- Primary amenorrhea is not having had a period by age 16.
- Secondary amenorrhea is the absence of periods in a woman who previously had regular menstrual cycles.
To have a period, a woman must have a normal, healthy:
- uterus, cervix or opening to the uterus, vagina, and ovaries
- pituitary gland
- hypothalamus, a structure within the skull that controls much of the body's hormone production
An abnormality in any of these may keep a woman from having a period.
What are the causes and risks of the condition?
Primary amenorrhea is usually due to late puberty rather than any permanent problem. The reason for this delay is generally not known, though it may be a family trait. Other possible causes are:
- a genetic disorder, such as Turner's syndrome
- a hormonal problem, such as an improperly functioning thyroid gland
Pregnancy is the most common reason for secondary amenorrhea. A woman's periods may also stop temporarily due to:
- birth control pills
- the birth control shot, such as medroxyprogesterone acetate
- levonorgestrel implants
A woman's periods may not start up again for a while after she stops using birth control pills, shots or implants. Usually, periods will start again within 3 to 6 months.
Secondary amenorrhea may also be linked to:
- emotional stress
- poor nutrition
- drugs, such as tranquilizers or antidepressants
- rapid weight loss or gain
- chronic systemic illnesses, such as kidney failure or cancer
- too much exercise
- recent surgery
- a hormonal imbalance, such as polycystic ovary syndrome (PCOS)
What are the treatments for the condition?
If amenorrhea has lasted less than 6 months, a woman may not need treatment unless she has worrisome symptoms or a problem is found:
- in her hormone levels
- on X-ray or ultrasound
Depending on the cause of amenorrhea, treatment varies. Diet and exercise generally correct abnormal periods due to obesity. Stress management and not exercising too much helps, too.
Because ovaries are not producing eggs or certain hormones, a woman may be given:
- birth control pills
- hormone replacement therapy (HRT) if she has reached menopause
- short-term oral progesterone pills or ovulation-inducing agents, such as clomiphene, for infertility
Birth control pills and HRT drugs contain estrogen and progesterone or sometimes progesterone alone. The hormones may be used to:
- induce a period
- prevent bone loss
Surgery may be required for:
- ovarian cysts
- defects in the uterus or vagina
Rarely, surgery is done when chromosome abnormalities are found.
What are the side effects of the treatments?
Hormones may cause minor side effects such as:
- breast tenderness
- PMS symptoms
- abdominal bloating
Occasionally, more serious side effects can occur with hormone therapy including blood clots, liver tumors, and endometrial cancer. Though these are quite rare, it is important for women to discuss the risks and benefits of hormone therapy with their healthcare provider.
Drugs to induce ovulation may trigger:
- hot flashes
- ovarian cysts
- mid-cycle pain
What happens after treatment for the condition?
When a younger woman has amenorrhea, normal periods often resume within a few years. Most women who are diagnosed and treated early can avoid surgery by taking hormones. If a woman wishes to get pregnant and not ovulating is the only infertility problem facing the couple, a success rate of 70% to 80% is possible.
After a woman stops taking birth control pills, she may not get a period for 2 to 3 months, though it may take a year or longer. If an unusual stress or illness has temporarily stopped a woman's periods, the problem will usually resolve on its own. It may recur at a later date.
How is the condition monitored?
If a woman misses more than one period, she should talk with her healthcare provider. It helps to:
- discuss any medicines or supplements she is taking
- keep a record of periods, marking down length, days between cycles, frequency, and flow patterns
- find out if there is a family history of infertility, ovarian cysts, or irregular cycles