We take it for granted that we'll have periods from puberty until middle age – and let's face it, most of us curse the onset of that monthly cycle. But what happens when your periods suddenly stop? It's fairly common to experience irregular periods from time to time – lifestyle changes and environmental factors such as shift work can make you late – but absent periods (amenorrhea) should always be checked out.
According to NICE (National Institute for Health and Care Excellence), it generally affects between 3-4% of people in the UK. "If a young woman who has regular periods doesn't have one for three months, she should go to her GP," says Dr Karen Morton, consultant in obstetrics and gynaecology at the Royal Surrey Hospital and founder of Dr Morton's. "It could just be an ovarian "hiccup" where you just didn't produce an egg – but it could be more serious." Below, we look at some of the most common reasons your periods might have stopped.
Severe stress can have a major affect on your periods. High levels of stress hormones such as cortisol in your body interfere with menstrual hormones surges, resulting in a cycle that's delayed – or that just stops.
Both mental and physical stress have the same affect on the body, says Dr Morton, and periods will return when the person is physiologically ready. "With mental stress, evolution is at work," she says. "It's something in the body and brain saying it's not ready for babies." This is likely to be so that you don't become pregnant in a threatening environment or when you are too thin.
Do it now: Find a stress management tool that works for you. This could be meditation, mindfulness or going out with friends. Exercise can help clear your mind, while working smarter – prioritising important tasks and accepting that your in-tray will always be full – may help reduce stress in your job.
Working out is good, right? Well, yes, usually – but if you exercise too much, your hormones will be disrupted in a similar way to when you're stressed.
According to the University of Michigan, around 66% of long-distance runners and ballet dancers experience amenorrhea, while it affects 81% of female bodybuilders.
"If you are an avid gym-goer or athlete and you have very little body fat, there is a good chance you will begin to skip periods and have anovular cycles," says Ms Shiran Irani, consultant gynaecologist at Spire Parkway Hospital in Solihull. "Even if you do have a cycle, you may have very light bleeds as the womb lining is thin."
Do it now: Regulate the amount of exercise you do each week. If you're a professional athlete, a GP specialising in sports medicine may be able to help you maintain performance as well as your cycle.
We know not all fat is good, but some fat is essential. If your body weight sinks too low, you may stop ovulating. "If you are underweight or you lose 15% of your bodyweight quickly, your body starts to think famine is around the corner and it shuts down systems that are not essential – among them your reproductive organs," explains Dr Marilyn Glenville, a nutritionist specialising in women's health. This also prevents a pregnancy when, as far as the body is concerned, there is not enough food to sustain both you and a baby.
Doctify obstetrician and gynaecologist, Mr Jayanta Chatterjee, agrees. "Once the appropriate weight gain is achieved and maintained – 90% of the predicted weight for height – periods often resume within a year."
Polycystic Ovary Syndrome (PCOS) affects one in five women in the UK. It's an endocrine disorder that has many symptoms, such as lack of or irregular periods, 'cysts' on the ovaries, fertility issues and weight gain. It can also cause excess body hair, acne, thinning hair and depression.
Not everyone shows all these signs, however – it affects women in different ways. Untreated, it can sometimes lead to more serious conditions such as type 2 diabetes and heart problems, so don't ignore it.
Do it now: If you think you may have PCOS, go and see your doctor. "Your GP will work out a plan and possibly refer you to a gynaecologist," says Dr Morton. If weight is part of the picture, she adds, then losing weight will dramatically affect how the ovaries work. The birth control pill can be used to induce periods if you're not trying to conceive.
The menopause is something that we associate with older women, but premature ovarian failure (POV) can happen to younger women, too. "The more we look for it in the under 40s, the more women we are picking up," says Ms Irani. She estimates that the incidence is 1%. The usual treatment for POV is hormone replacement therapy. "In younger women, it is best given via the contraceptive pill so as not to have the HRT stigma," explains Ms Irani. "It also allows them to feel normal by having a period. These women have been known to get pregnant, and there are now cases of women who have got pregnant with IVF."