During your menstrual period, your uterus contracts to help expel its lining. Hormonelike substances (prostaglandins) involved in pain and inflammation trigger the uterine muscle contractions. Higher levels of prostaglandins are associated with more-severe menstrual cramps.

Are cramps The most painful thing?

But gynecologist Dr. Jen Gunter, who writes a popular women's health blog, has called that comparison into question. In a new post published Friday, Gunter wrote that period cramps are often much more painful than heart attacks.

How painful are period cramps?

Most women get it at some point in their lives. It's usually felt as painful muscle cramps in the tummy, which can spread to the back and thighs. The pain sometimes comes in intense spasms, while at other times it may be dull but more constant. It may also vary with each period.