Periods can be unpredictable—sometimes, you have a super heavy flow; other times, it's light. Sometimes, you have accompanying cramps; other times, you don't. And it's common for your cycle length to fluctuate between 21 and 35 days.

But what if your period comes very rarely – like only a handful of times a year – or none at all? Is that normal? What is causing it? Can you get your period back? And can you still have children?

Those and plenty more questions are answered below.

What is amenorrhea?

Amenorrhea is the medical term used to describe the absence of menstruation or the lack of a period. It is classified as either primary amenorrhea or secondary amenorrhea. Primary amenorrhea is the absence of a period by age 15 or after, while secondary is not having a period for more than 3 months in those who previously had regular cycles or missing a period for more than 6 months with previously irregular cycles. Although not having your period can seem like a medical condition, amenorrhea is actually a symptom of something else – a hormonal imbalance in your body.

If a woman has amenorrhea, she is not ovulating regularly, therefore making it harder to conceive by not knowing the appropriate fertile window. In a healthy reproductive system, ovulation occurs, and if pregnancy is not achieved, menstruation follows. In the absence of pregnancy, menstruation almost always follows ovulation, so it’s safe to assume ovulation does not occur when there is no menstruation.

What causes amenorrhea?

While amenorrhea is caused by a hormonal imbalance, that imbalance can have several roots.

PCOS

The most common cause of amenorrhea is Polycystic Ovary Syndrome (PCOS), marked by irregular or absent ovulation. In the case of PCOS that causes amenorrhea, no ovulation would be present. While the definitive causes of PCOS are still being studied, doctors know that PCOS is fundamentally about a disrupted interplay of hormones in a woman’s reproductive system.

For example, women with PCOS usually have high levels of Luteinizing Hormone (LH) and low levels of Follicle Stimulating Hormone (FSH), an imbalance that prevents the eggs inside their follicles from growing, maturing, and selecting a lead follicle to ovulate that cycle to release an egg primed for fertilization.

Without a dominant follicle, there is no ovulation and, in turn, no period. Women with PCOS can also have high androgen levels (testosterone), which can often cause acne and unwanted hair growth on the face or central body (known as hirsutism). In addition, insulin resistance and trouble losing weight are markers of PCOS. However, recent research has shown that there are multiple phenotypes of PCOS. The condition presents itself in numerous ways that go beyond the common misconception that it is predominantly a problem for overweight women, and is often referred to as ‘lean PCOS’.

If you identify with some of the above, your amenorrhea may be PCOS-related. PCOS can be diagnosed through blood work and transvaginal ultrasound. An elevated Anti-Mullerian Hormone (AMH) result can indicate a high follicle count, meaning an abundant ovarian reserve, also identified on ultrasound as polycystic ovaries. Two out of three criteria can often be used to diagnose PCOS, including a history of irregular cycles, having polycystic ovaries on ultrasound, and/or either clinical symptoms or bloodwork results of elevated androgens.

Hypothalamic dysfunction

Another possible, although less common, cause of amenorrhea is hypothalamic dysfunction. This is when the hypothalamus, the hormonal control center of the female reproductive system located in the brain, is not working correctly.

In this case, the body does not produce enough LH or FSH, again compromising ovulation and menstruation, leading to amenorrhea and anovulatory infertility. Hypothalamic dysfunction-related amenorrhea is common for athletes and women who either over-exercise or under-eat and overall have low body weight or may have lost weight rapidly. Why? Healthy fats are vital to proper hormonal function, and not enough of them can lead to hormonal issues.

Prolactin and thyroid issues

Finally, two other possible causes of amenorrhea center around the hormone prolactin and the thyroid hormones. Both a high prolactin level and irregularities with thyroid hormones can cause amenorrhea.

No matter the cause of amenorrhea, the result is the same: a lack of a period and infertility due to anovulation.

Will amenorrhea last forever? Is it possible to get my period back?

The good news is that you don’t have to be stuck with amenorrhea – or the resulting fertility challenges. There is help available, and it’s possible to not only get your period back but also to ovulate and conceive.

Depending on the cause of the amenorrhea, medications may not be needed. For example, in the case of hypothalamic dysfunction caused by excessive exercise, decreasing vigorous activity and increasing caloric and fat intake could normalize your hormones over several months and bring regular cycles. Similarly, women with weight-induced PCOS may be able to get hormones into balance and see a return of their period with lifestyle changes.

How can I treat amenorrhea?

The treatment path for amenorrhea completely depends on its root cause as well as the desired outcome.

What if I want my period back with regular cycles?

If you are not trying to conceive and hope for regular cycles, it is important to see your doctor and be appropriately assessed with diagnostic tests for the root cause. It is always best to be informed and guided by your situation so that you may appropriately make decisions to better your health and ensure you can meet your family-building goals in the future.

How can I treat my amenorrhea if I want to conceive?

The primary treatment for amenorrhea for women who want to conceive is to bring about the onset of ovulation. This can be done (and is usually successful) by taking medications that stimulate the production of FSH and LH in the body – medicines like Clomid and Letrozole.

These medications will help grow and mature a woman's eggs and prepare one, two, or more follicles – for ovulation. An increase in follicles, such as greater than 4, slightly increases the risk of twins. These medications can be taken orally before trying to conceive on your own or with fertility intervention such as Intrauterine Insemination (IUI). If pregnancy does not occur via these methods, it is important to follow up with your healthcare team and discuss possible other options.

Bottom line?

Amenorrhea can be unsettling and sometimes concerning, but understanding that it is a symptom that usually has a solution, whether through lifestyle changes or medication, is the first step to getting your period back or starting your journey to parenthood. Both are within reach.