Period cramps: why they happen and what actually helps

What period cramps feel like

Most people who menstruate get some cramping. For many it's a dull, heavy ache low in the tummy. For others it comes in waves, spreads into the lower back and thighs, and brings nausea, loose poos or a headache along for the ride. Doctors call painful periods dysmenorrhea. When there's no underlying condition, it's called primary dysmenorrhea, and it's by far the most common kind.

• A cramping or squeezing pain in the lower belly, often in waves
• A constant dull ache underneath the waves
• Pain that spreads to the lower back or down the legs
• Nausea, diarrhea, dizziness or a headache at the same time
• Usually worst on the first day or two of bleeding, then easing

Why your uterus cramps

In the last days of your cycle, progesterone falls. That drop tells the uterine lining to break down, and the lining releases prostaglandins. These hormone-like chemicals make the uterine muscle contract to push the lining out. Strong contractions can briefly squeeze the blood vessels feeding the muscle, and that short drop in oxygen is what hurts. Higher prostaglandin levels mean stronger cramps, which is why the first day or two, when the most lining is shed, usually feel worst.

Prostaglandins don't stay put. They also reach the bowel and other muscles, which explains the period poops, nausea and achy legs that often turn up with cramps.

What actually helps period cramps

1. Take an anti-inflammatory early

Non-steroidal anti-inflammatories (NSAIDs) such as ibuprofen or naproxen lower prostaglandin production, so they treat the cause rather than just masking pain. A Cochrane review found NSAIDs work well for period pain. Timing matters: take them at the first sign of cramps or bleeding, or the day before if your period is very predictable, and keep to the dose on the pack. Check with a pharmacist first if you have asthma, stomach ulcers, kidney problems or could be pregnant.

2. Use heat

A hot water bottle, a stick-on heat patch or a warm bath relaxes the muscle and is surprisingly effective. In small trials, continuous low-level heat on the lower belly eased cramps about as well as ibuprofen. Wrap anything hot in a cloth to protect your skin.

3. Move a little

It's the last thing you feel like doing, but gentle exercise helps. A Cochrane review of exercise for period pain found that regular exercise, about 45 to 60 minutes three or more times a week, may reduce pain intensity. On the day itself, a walk, stretching or yoga poses that open the hips can take the edge off.

4. If cramps keep winning

If over-the-counter options don't help, a doctor can talk about hormonal options. The combined pill, the hormonal IUD, the implant or the injection often make periods lighter and less painful. Some people also find TENS machines (small devices that send gentle electrical pulses through the skin) helpful.

Cramps, mood and energy

Pain is tiring, and it makes everything else feel heavier. Many people notice they're more irritable or low on the first day of their period simply because they're hurting and sleeping badly. That's not a character flaw. Logging cramps alongside your mood for a couple of cycles often shows a clear pattern: the hard day is predictable, and so is the relief that follows. Read more about mood during your period.

When period cramps aren't normal

Pain that starts years after your periods began, gets steadily worse, or comes with other symptoms can be secondary dysmenorrhea: pain caused by a condition such as endometriosis, adenomyosis, fibroids or pelvic inflammatory disease. These are treatable, and you deserve to be taken seriously.