A little bit of stress can actually be healthy (like in the case of exercise), but when most of us talk about stress we’re referring to the bad, on-the-edge-of-burnout kind. Excessive or chronic stress has a huge impact on your wellbeing—and yes, even your period. 

Stress can make your periods more heavy, show up late, or stop altogether. Ironically, a late or missed period is the last thing you need when you’re already stressed TF out. 

But why does stress interfere with your menstrual cycle? The short answer is: hormones (it's always hormones). Stress causes a rise in certain hormones that affect the production and interaction of reproductive hormones. 

There are many reasons why your period may be MIA, like hormonal contraception, medication, illness, or sudden weight loss. But when you’re stressed, your body goes into “fight or flight” response as a means to deal with a potential threat (ie. stress). 

Stress activates a hormonal pathway in our brain called the hypothalamic-pituitary-adrenal (HPA) axis, our central stress response system. 

The HPA axis is the feedback loop of signals between the hypothalamus, pituitary gland, and adrenal glands and plays an important role in many body functions, including digestion, immune system, mood, libido, energy and, of course, stress response.

Stress interferes with this communication feed between your brain and adrenal glands, and when the HPA axis is activated, your brain signals your body to produce two hormones: corticotropin-releasing hormone (CRH) and cortisol (aptly dubbed the “stress hormone”). 

Increased CRH and cortisol can suppress normal levels of the reproductive hormones that control your menstrual cycle, chiefly oestrogen and progesterone, in turn causing abnormal ovulation (or no ovulation at all). 

When CRH and cortisol levels are too high, your brain is essentially saying "hell no" and decides that you're too stressed to handle a pregnancy—or even carry it to term. Research has found a link between increased CRH, cortisol, and both preterm labour and miscarriage. 

Cortisol can delay, or even prevent, ovulation. It also interferes with the production of progesterone, and decreased progesterone can sometimes cause spotting. So when you’re stressed, your period may show up late, early, or stop altogether (known as amenorrhea). It could even be heavier and more painful. 

There’s no one way your period may be affected when you’re stressed, as it highly depends on how much stress you can handle and how regular your period is. But any shift in hormonal function has the capacity to change bleeding patterns. 

In fact, a 2004 study found a significant link between stress and dysmenorrhea. The results showed that women with high stress were twice as likely to experience painful periods. 

Although there is no health benefit to bleeding every month, periods are like your fifth vital sign. They can be a great indicator of when things are a bit off, sort of like your body’s way of warning you. 

Whether you’re stressed because of burnout, a recent breakup, the loss of a loved one, school deadlines, personal illness or any other curveball life may throw at you, your period could react accordingly. 

Everyone experiences stress to some degree, but if it’s interfering with your menstrual health and affecting your cycle, it’s a good idea to speak to your GP or healthcare provider.