Periods
Why do my periods hurt so much?
Period pain comes from strong contractions of the uterus, driven by chemicals called prostaglandins. Heat and anti-inflammatory painkillers help most people. Pain severe enough to stop you doing normal things is not something to put up with, because there is usually a treatable cause.
What this does and does not tell you
This is general information, not a diagnosis. Only a clinician can examine you, take your history and run tests. The same symptom has different causes in different people.
If something is sudden, severe, or getting worse quickly, get medical advice rather than reading on.