Experts say amenorrhea develops in about 1 in 25 women who are not currently pregnant, breastfeeding, or menopausal.  And in many cases, the issue is tied to restrictive eating disorders, including anorexia nervosa (AN), when severely limited food intake and excessive exercise can lead to extreme weight loss.
Regardless, the disruption of a normal menstrual cycle for women of childbearing age is often an indication of a significant health problem. But if the issue is connected to an eating disorder, there are treatment programs that can help.
What Is Amenorrhea?
Amenorrhea is not the same thing as an occasionally-skipped period.
The diagnostic criterion for amenorrhea is specific, including: 
- Primary amenorrhea: When a girl doesn’t get her first menstrual period by age 15.
- Secondary amenorrhea: When adult women who’ve already had their period don’t menstruate for three months or longer.
The absence of menstruation can be an indication of disrupted hormone levels, which can lead to an increased risk of developing several medical complications. For many women with anorexia nervosa, this change in body functions may be the first physical sign that something is wrong.
Amenorrhea vs. Irregular Periods
On average, biological adolescent girls have their first periods by age 12.  But once they begin menstruation, their cycle can be erratic for several years.
It’s not unusual for young girls to skip a month or two between menstrual periods as their hormone levels even out. And it’s possible for some women to experience less-predictable cycles throughout their lives.
Certain conditions, including endometriosis and uterine polyps, could lead to irregular periods.
And a number of factors can cause even healthy women to skip a period, including:
- Gaining weight
- Weight loss, particularly significant weight loss
- A change in diet
- Excessive exercise or a change in workout routine
- High levels of stress
- Other disruptions to a regular routine
When the loss of menstrual function happens for these reasons, it’s sometimes called functional hypothalamic amenorrhea. But amenorrhea related to anorexia nervosa or other eating disorders can lead to prolonged amenorrhea, so long as body weight remains low.
Menstruation is the byproduct of several bodily systems working in tandem. So the absence of a period can be an indication of problems in several different areas.
As such, there are a number of other symptoms that often accompany primary or secondary amenorrhea, including: 
- Breast changes
- Excessive facial hair
- Energy deficits
- Low estrogen levels
- Scalp hair loss
- Vision changes
- Possible reproductive issues
Still, it’s possible for a woman to have amenorrhea without experiencing any of these additional symptoms.
Amenorrhea and Anorexia Nervosa
Anorexia nervosa is a mental health disorder, but it also has a deep impact on the body. All told, the condition can contribute to amenorrhea in a number of different ways.
Some of the primary aspects of anorexia nervosa are a fixation on body composition, shape, and size, severe food restriction, and an overpowering desire to lose or control weight. In most cases, this leads people with the condition to have a low body weight.
Carrying less body fat can lead to amenorrhea. The substance is an integral part of hormone production, and can lead to complications in hormone regulation that cause disrupted menstrual cycles.
The absence of body fat also moves the body into “starvation mode,” which commonly causes metabolic processes to stop. Functional hypothalamic amenorrhea is often the result. 
Many people who experience anorexia nervosa or other eating disorders turn to excessive exercise to help them with weight loss. This can also lead to a low body weight and a low body fat percentage, which can disrupt the body’s hormonal and metabolic processes.
Exercise can also release certain stress hormones, which can cause the body to delay or stop the production of reproductive hormones, leading to functional hypothalamic amenorrhea. This is why many female athletes, even those at a healthy weight who eat a nutritious diet, may experience amenorrhea.
The female body is designed to menstruate, but the activity requires vitamins, minerals, and micronutrients. And a nutritional imbalance could cause menstruation to stop.
According to some studies, people with AN tend to eat diets low in fat and micronutrients, choosing instead to supplement with caffeine and vegetables. 
This limited caloric intake often leads to nutritional deficiencies and can cause many women to experience amenorrhea.
When the human body is under stress, it often shuts down unessential activities. This leaves room for energy to be devoted to fight-or-flight instincts.
But chronic stress can lead to an energy imbalance that can cause internal damage and other health problems, including the hormonal disruptions that lead to amenorrhea.
Stress has also long been linked to the development and sustainment of anorexia nervosa.  And the eating disorder itself can, in turn, be a source of additional stress.
Amenorrhea and Other Health Complications
While the absence of menstruation is not a danger in and of itself, it’s often an indication of a significant problem.
Women with hypothalamic amenorrhea or adolescent girls with primary amenorrhea may also be at an increased risk of certain medical complications.
If you’re experiencing amenorrhea, it’s important to contact your doctor.
Amenorrhea has been linked to a number of bone health problems and abnormalities. 
Many of the hormones involved in menstruation also play a role in building strong, healthy bones, and the same disruptions that cause an absent menstrual cycle could also have an effect on this bodily system.
It is not unusual for women struggling with amenorrhea to experience bone loss or a loss of bone density, leading to bones that are thin, porous, and prone to breaking.
Amenorrhea can also indicate issues with the pituitary gland. Much of the body’s hormone production takes place in this part of the body, so a missing period can be a cause or effect of pituitary complications.
Some of the most common pituitary issues that could lead to amenorrhea include tumors, hypothyroidism, and adrenal disorders. 
Reproductive health complications are another potential effect of amenorrhea. Women experiencing this condition, whether due to an eating disorder, a hormonal dysfunction, or any other reason, may experience difficulty becoming pregnant or have more difficult pregnancies.
Still, unplanned pregnancy is possible at any time, even when struggling with amenorrhea, so women should still be careful when engaging in intercourse.
There is no official treatment recommended for amenorrhea, but there are some ways to help alleviate the issue.
For women with anorexia nervosa or others at a low body weight, weight restoration is a crucial aspect of recovering a normal menstrual cycle. Many women see a resumption of menses after returning to a healthy weight.
Especially for those with anorexia nervosa, weight gain may be difficult. Inpatient treatment could be necessary to help someone safely put back on a significant amount of weight.
Reproductive medicine can also benefit some people with amenorrhea, with some types of birth control or other hormonal therapies sometimes used to help kick-start the process, particularly in cases where pituitary or other hormonal issues are in play.
Finding Help for Anorexia Nervosa
In cases where anorexia nervosa leads to amenorrhea, the best chance for restoring a regular menstrual cycle is by finding help for AN.
If you or a loved one are struggling with anorexia nervosa, you should seek out help as soon as possible. Amenorrhea is not the only potential side effect of the condition, and if left untreated, AN can cause severe damage or even death.
You might want to start by reaching out to your primary care physician or therapist. These healthcare professionals are trained in how to look for eating disorders and can offer advice for how and where to seek out treatment.
Overall, it’s important to remember that anorexia nervosa can be treated. Seeking out help is the first step you can take toward a happier and healthier future.
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