Mittelschmerz is German for “middle-time pain.” Dysmenorrhea is Greek for “difficult” (in other words, “painful”) periods. Both are natural, neither is dangerous, both can make patients & clinicians worry.
Mittelschmerz occurs when the ovary releases an egg. Many women don’t feel anything, others feel mild discomfort, a few feel significant pain. Mittelschmerz happens in the middle of the menstrual cycle. It’s most reliably measured as two weeks before the first day of the next period. This is easy for women whose periods are regular, but virtually impossible if irregular.
We diagnose Mittelschmerz by counting (see previous paragraph). If it happens for the first time, without a pattern, it’s difficult or impossible to be sure. We also need to be exact about periods. If a recent period was unusually long or short, early or late, there’s a possibility it wasn’t really a period. For example, conception of pregnancy happens in the middle of the cycle; then 2 weeks later, at the time of the first missed period, there may be spotting as the newly-formed fetus implants (attaches itself) to the uterus. So if pain begins a few weeks later, that would be the time for an Ectopic Pregnancy. Moral: Lower abdominal or pelvic pain plus irregular periods requires a pregnancy test.
Dysmenorrhea means menstrual cramps. Usually this is a pattern, and a woman doesn’t seek medical care unless she simply wants pain medication. Dysmenorrhea also occurs with Endometriosis, which should always be considered. New “menstrual cramps” that never occurred before could really be a complication of unrealized pregnancy. Especially if this period or the one before are also irregular, a pregnancy test should be done.