Prostaglandins: definition and meaning
Prostaglandins are hormone-like chemicals made by many tissues in the body that control inflammation, pain and muscle contraction. Before and during a period, the uterine lining releases prostaglandins that make the uterus contract to shed it. Higher levels are linked to stronger period cramps, plus diarrhea, nausea and headaches.
How prostaglandins cause period symptoms
- Cramps: strong uterine contractions squeeze blood vessels, briefly cutting oxygen to the muscle, which hurts. This is primary dysmenorrhea.
- Period poop: prostaglandins also reach the bowel and speed it up, causing loose stools.
- Nausea and headaches: they can affect the stomach and blood vessels elsewhere.
- Back and thigh ache: pain spreads along shared nerve pathways.
Levels are highest in the first day or two of bleeding, which is why cramps usually peak then. See period cramps and why periods make you poop.
What lowers prostaglandins
Anti-inflammatory painkillers such as ibuprofen and naproxen block the enzymes that make prostaglandins. They work best taken at the first sign of a period, or a day before if your cycle is predictable, and taken regularly through the worst days. Hormonal contraception thins the lining, so less prostaglandin is released. Heat and movement help with the pain too.
Prostaglandins beyond periods
They're also involved in menstrual migraine, fever, labor (synthetic versions are used to induce it) and protecting the stomach lining, which is why anti-inflammatories can upset the stomach.
See a doctor if cramps stop you doing normal things, painkillers don't help, or pain is getting worse over time. Conditions like endometriosis or adenomyosis can cause secondary dysmenorrhea.
Frequently asked questions
Why do my cramps hurt more on day one?
Prostaglandin levels peak as the lining starts to shed, so the first 1 to 2 days usually hurt the most.
Do prostaglandins affect mood?
Not directly in a well-studied way, but pain, poor sleep and bowel upset on heavy days easily drag mood and energy down.
Sources
This page is for information only and isn鈥檛 medical advice. If something worries you, please talk to a doctor.
Keep reading
Period cramps: why they happen and what actually helpsPeriod cramps explained kindly: why your uterus cramps, how long it lasts, what really helps (timing matters) and the signs that need a doctor.Dysmenorrhea: definition and meaningDysmenorrhea is the medical term for painful periods. The difference between primary and secondary dysmenorrhea, what helps, and when to see a doctor.Why does your period make you poop more?Period poop is real. Prostaglandins that make your uterus cramp also speed up your bowels. Why it happens, why it can hurt, and how to calm your gut.What helps period cramps? Remedies that workWhat helps period cramps? Painkillers, heat, exercise, hormonal options and a few supplements, ranked by evidence. Plus when period pain needs a doctor.Menstrual phase: definition and meaningThe menstrual phase is the part of your cycle when you have your period, usually days 1 to 5. What happens to hormones, energy and mood during it.