Understanding Dysmenorrhea: What causes your period cramps

Medically reviewed by Dr. Fatema M Dawoodbhoy

Dysmenorrhea is divided into two categories: primary and secondary. Primary dysmenorrhea is a symptom of normal menstruation, but secondary dysmenorrhea is associated with an underlying health condition, the most common being endometriosis.  Secondary dysmenorrhea can last for days, happen outside of your period, and does not typically get better even as the person gets older.   

Menstrual cramps are typically felt in your pelvic area, which is around the lower abdomen, but  the pain can also radiate to the back and down the legs.. Since pain is subjective, it can be difficult to quantify the pain on a scale. Patients with endometriosis have described dysmenorrhea pain in many ways depending on its severity. Some have described it as a ‘’sort of cramp’’, a ‘’stabbing pain’’, and ‘’muscles slowly being ripped out’’. One sufferer even stated ‘’my pain was 9/10 and was only not 10/10 because I knew I was not literally dying’’.  

We spoke to members of our endometriosis panel to better understand their experiences dealing with severe period cramps. @endo.periods.etc, who also runs a popular endometriosis Instagram account, has been suffering with painful periods since she was 11, and Suzanne started medical treatment for her period pain when she was just 12 years old. 

Dysmenorrhea can occur in menstruating individuals with and without an underlying health condition. Period cramps can be normal – but to a certain extent. When your progesterone levels drop, the endometrium (the lining of the uterus) sheds, releasing hormone-like chemicals called prostaglandins. While the prostaglandins causes the uterus to contract to help the uterine lining shed, it also pinches the blood vessels, reducing blood flow and oxygen to the muscle. This leads to cramps, which causes pain. However, if you feel like your cramps are affecting your quality of life, this is not normal and you should speak to a GP or physician.  

Period cramps are much more intense in endometriosis compared to a normal period due to hormonal imbalance. Steroid hormones like oestrogen and progesterone help control build-up and shedding of the endometrium. When these hormones are imbalanced, they contribute to more severe dysmenorrhea.

Inflammation 

As the thick endometrium layer sheds and bleeds, inflammation occurs at the site as immune cells gather to help clear the damaged tissue. In endometriosis, the presence of lesions outside the uterus worsens the swelling and pain because they also bleed without a place to escape, which leads to more inflammation.  

Research has shown those with endometriosis have more frequent and stronger uterine contractions.  This could be due to hypoxia, a lack of oxygen. The concentration of prostaglandins is higher in the menstrual blood of patients with endometriosis, causing the uterus to contract more and reducing oxygen flow to the muscles, ultimately resulting in more severe and painful cramps.  

Scar tissue 

The presence of endometrial lesions can cause inflammation, leading to the formation of scar tissue. This can bind organs (such as the bowels) together, reducing mobility and causing pain when moving or when the organ contracts and relaxes.    

An emerging strategy to tackle endometriosis symptoms are botulinum (Botox) injections in the uterus or pelvic floor muscle. Although primarily used to reduce chronic pelvic pain (cramps that happen outside of your period), a significant population of sufferers felt that it helped with severe dysmenorrhea.