Image of a woman's jeans and underwear - Libresse

It’s common for women to worry that their periods aren’t normal – mainly because, when they first start, periods do take some getting used to.

But don’t worry. That ‘am I normal?’ thing soon wears off. And anyway, when it comes to when they start, how long they last, and the symptoms you get, a ‘normal’ period is a pretty broad thing.

On average, women start menstruating between 11 and 14 years of age. A normal period cycle lasts 28 days, but can vary from 21 to 35 days. And during puberty they can last even longer, and take a while to settle down. After puberty, most women develop a regular menstrual cycle, with around the same length of time between periods, and the same length of period. Menstrual bleeding usually lasts two to seven days, with the average being five days.

Once your period starts, the bleeding will usually be the heaviest in the first two days. The amount of blood lost in a normal period is about two to three tablespoons or 30-40ml. But don’t forget that it always looks like more than it is. Some women bleed more heavily than this and may need to change their sanitary towel more frequently. Or switch to a higher absorbency.

When a woman’s menstrual flow is at its heaviest, the blood tends to be red. On lighter days, it may be pink, brown or black – this is all completely normal. Hormonal changes before periods can also cause physical and emotional symptoms. Like diarrhoea or back pain, feeling bloated and nauseous, or your breasts getting bigger. Some women also feel sad and a bit weepy or irritable before a period. These are all signs of what’s known as PMS or premenstrual syndrome. Not fun, but all perfectly normal

Over-the-counter painkillers, some gentle exercise and applying a heat pad or hot water bottle to the tummy area can ease pain and discomfort. Snuggling up under a duvet is also highly recommended. Your doctor may prescribe a stronger painkiller if period pains are a real problem. Symptoms such as feeling bloated, mood swings and irritability usually improve when a period starts and disappear completely shortly after it finishes.

Did you know?

6.5
years of their life women spend menstruating [1]
15
million: number of menstruating women in the UK [2]
50
the average age a woman menstruates until [3]

Continue learning

Explore more