Missed Your Period? Here Are 9 Possible Reasons Why

1. You're not eating enough.
Aside from, you know, being pregnant.
Aside from, you know, being pregnant.

Periods are a peculiar experience -- you hate mega loathe them when they come, but if you miss one, you suddenly wish they would return.

Chances are you've experienced missed periods at some point in your life. While your first thought is 'well sh*t, I'm pregnant', once you rule that out, you head into a spiral of stress and anxiety.

Is there something wrong with me? What if I'm infertile? Do I have cancer? Hooooly moly.

Don't worry, loss of period (also known as amenhorrea) is very common, and there are various reasons for it, many of which are easily treatable.

"From a medical perspective, there's two types of amenorrhea," Dr Clare Ballingall, a GP and chair of RACGP Tasmania, told The Huffington Post Australia.

Loss of period doesn't always equal pregnancy.
Loss of period doesn't always equal pregnancy.

"There's primary amenorrhea, which is probably not what most people know about. This is when people fail to have a period beyond the age of 16, when there is normally a problem. Often there are structural issues in the vagina or uterus, or genetic problems.

"The more common is secondary amenorrhea. That's defined as loss of period for more than three cycles in someone who previously had a regular cycle."

While it's easy to become panicky and worried about missing a period, Ballingall urges women to take it easy.

"The one thing I would say is that it's okay to miss a couple of cycles. Because there's not that much information out there about periods and there's not that many places women can go to learn more, people freak out and it causes a lot of anxiety," Ballingall said.

"If you miss a period or two, it's not something we would worry about. We encourage girls to come in and talk about their periods."

Just be healthy and be kind to yourself, as always.

If you've ever wondered if your general health and lifestyle affects your menstrual cycle, here's a definitive answer: it does.

"Someone's general health really does have an impact on their period in lots of different ways, some subtle and not-so-subtle," Ballingall said.

"The thing about periods is they're just still not talked about and are shrouded in a bit of mystery and taboo. We tend to be this open society where we talk about sex -- every women's magazine is full of sex predilections, sex toys and fetishes. But really, when do you read an article about periods? It's just not talked about.

"There should be an increased awareness about health and periods, and I think it's going to be a huge problem."

Here are nine common reasons for loss of period -- aside from being pregnant.

1. You're not eating enough.

According to Ballingall, eating patterns directly impact a woman's cycle.

"If you're very underweight and have a low BMI, periods can stop. We think that any person with a BMI under 18.5 is probably too light, and that's when they can start losing their periods," Ballingall said.

This is where eating disorders usually come into play. Approximately four percent of people in Australia live with an eating disorder at any given time.

"Though I wonder if it's not a bit more than that, perhaps that's just the people admitting to these," Ballingall said. "We know that restrictive eating affects the hypothalamus in the brain.

"There are also new hormones we've found out in the last 10 years that are involved in affecting the hypothalamus. One of them is ghrelin. Rapid or enforced weight loss increases levels of ghrelin and that directly affects and reduces the pulse hormones from the hypothalamus."

If you are living with an eating disorder, see your GP and talk to someone you trust.
If you are living with an eating disorder, see your GP and talk to someone you trust.

When a person has a very low body weight, there's also a reduction in a hormone called leptin.

"That is directly related to having little fat, and again, that can reduce the pulses from the brain," Ballingall said.

"There's another theory, that people living with an eating disorder are under a lot of stress. It's not a relaxing state and people tend to be very unhappy. It's a double whammy -- there's the hormonal side, but also the stress."

2. You're overweight.

Equally, high BMI or high body weight negatively impacts fertility and periods.

"We focus on people being underweight and not having periods, but it's mostly the other way around. We know that if you're overweight, you're going to have a problem," Ballingall said.

"Certainly in my practice, the majority of people I've seen who have lost their periods is due to raised body weight and a BMI of over 30.

"The obesity crisis is a huge problem, it's a slow train coming and it's going to hit us soon. I think this will become a much more frequent reason for people losing their periods.

"With obesity and loss of periods, the other health issues are a much increased risk of diabetes, heart disease, and sometimes endometriosis and cancer in later life."

A 'healthy' range BMI is between 20-25.
A 'healthy' range BMI is between 20-25.

3. You're breastfeeding.

Still haven't got your period back after having your bub? Breastfeeding can delay the return of your cycle.

"A lot of people don't have their period when they are breastfeeding, this is a really common cause."

4. You're on certain contraceptives (or have just come off them).

There's many contraceptives that stop you from having your period, as well.

"We've moved into the space where we're trying to encourage people not to take the pill and use long-acting reversible contraceptive -- Implanon and Mirena coil, specifically. Most women with these don't have a period," Ballingall said.

"People who stop the pill can also have no periods for a while, which often causes anxiety. After the Depo-Provera (there may be) a delay of periods coming back, as well."

5. You're stressed, anxious or depressed.

"Commonly, mental health issues can play a part in lack of periods," Ballingall said. "If you get super stressed, we know that periods will, for some people, just vanish."

This is thought to be because stress can cause a change in hormones.

"We think that stress acts on the hypothalamus," Ballingall said.

"Your periods aren't just your uterus and ovaries, it starts in the brain in a place called the hypothalamus. It has got a pulsatile release of a hormone which affects the pituitary gland, and that puts out different hormones, and those hormones act on the ovaries, which then produce the eggs. It's a multilevel process."

We have all heard (or perhaps experienced) how stress can affect fertility.

"Interestingly, in my own practice I have a lovely couple who are trying to conceive. She's been so stressed, it's actually stopped her periods," Ballingall said. "Your period stops, and that makes you more stressed, and it's a cycle."

6. You have underlying medical conditions.

Don't stress out yet, but certain medical conditions can cause amenorrhea.

"An acute illness can have an effect. If someone has a sudden terrible illness, we think it's the same process as stress and can stop you from having your period," Ballingall told HuffPost Australia.

"There are some medical problems that cause periods to disappear, but equally it can cause periods to get much heavier. This is usually related to thyroid problems, like an underactive and overactive thyroid."

Meditation and gentle exercise like yoga can help manage stress.
Meditation and gentle exercise like yoga can help manage stress.

7. You're exercising too much.

Exercising intensely five days a week and running 20 kilometres a week? Excessive exercise is another potential cause of amenorrhea.

"Elite athletes or marathon runners, or people who are just over-exercising, can also lose their periods," Ballingall said.

"We think, again, it's because of the stress on the body. There's that cross over, as well, because these people often have a low body mass index. Perhaps they're not under-eating, but aren't eating enough to keep up with their training. We think estrogen levels go down with less fat."

8. You're going through early menopause.

"The other thing which we should be thinking about when periods stop is premature menopause. Women who have menopause below the age of 45 is something we should look out for," Ballingall said.

"It's not very common but it is a cause."

Be kind to yourself (and cuddle cute cats).
Be kind to yourself (and cuddle cute cats).

9. You have PCOS.

PCOS is also becoming more common as the obesity rate goes up, Ballingall explained.

"The causes of PCOS aren't clear. There may be a genetic component," Ballingall said.

"It's related to insulin resistance, as well. The larger you get, the more resistant you become to insulin. That doesn't directly cause you to have PCOS, but if you've got the genetic predisposition, that might be an issue for you.

"When you have PCOS, it increases the male hormones we carry (testosterone) and that can stop people's periods, which is really alarming. PCOS doesn't always cause no periods, it can just cause reduced periods, and we know it reduces ovulation."

Basically, there are many reasons why your period may be AWOL, and it becomes particularly tricky because many factors overlap.

If in doubt, talk to your GP.

"Absolutely, and that's why there's not a clear answer for why it happens," Ballingall told HuffPost Australia. "Just be healthy and be kind to yourself, as always.

"If you are having heavy or painful periods, or they are pesky, see your GP or Family Planning. People literally think the pill is it, or they think if their mum had heavy periods then it's normal and just part of life."

If you are underweight or overweight and have missed periods, the solution may be simple.

"For overweight women, exercise more and eat less. And on the other end of the spectrum, for the treatment of losing your period when you're too thin, is to exercise less and eat more.

"If in doubt, talk to your GP. The Jean Hailes website is also a great resource for information about periods and women's health."

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