Periods

What a period is, what a cycle looks like, how to deal with pain, how to use pads, tampons, cups and period underwear safely, and when something is worth checking. This page is for anyone who gets periods, of any gender.

What a period is

From puberty on, an ovary releases an egg each month, and the lining of the uterus grows thicker. If no pregnancy happens, the lining breaks down and flows out through the vagina. That's a period.¹

Verified with: ACOG, Mayo Clinic

Most people start their periods somewhere between 11 and 14, but some start earlier or later. The NHS says they can start as early as 8.²¹³ Periods are a normal, healthy part of life.⁴

Verified with: ACOG, Cleveland Clinic, Healthdirect Australia, NHS

What's normal

• The first few periods may be very light, sometimes just a few spots of reddish brown blood, and may last only a few days.⁴

  Verified with: ACOG, Cleveland Clinic, NHS

• A period lasting anywhere from 2 to 7 days is normal.⁴

  Verified with: ACOG, NHS, Cleveland Clinic

• Bleeding tends to be heaviest in the first 2 days. The blood can range from red to pink or brown.⁵

  Verified with: NHS, Healthdirect Australia, Cleveland Clinic

• The NHS says that over a whole period, people lose about 20 to 90ml of blood (about 1 to 5 tablespoons), though some people bleed more heavily than this.⁵ Healthdirect Australia counts more than 80ml as heavy.⁶ Nobody has to measure this.

  Source: NHS, Healthdirect Australia, Cleveland Clinic

A cycle is counted from the first day of bleeding to the first day of the next period. The average is about 28 days. For the first years after periods start, anything from 21 to 45 days is normal. After that, it's usually about 21 to 35 days. ACOG, the US body for gynaecologists, says it can take 6 years or more for the cycle to get regular.⁴⁷⁵⁸⁹

Verified with: ACOG, Current Problems in Pediatric and Adolescent Health Care, NHS, Cleveland Clinic, Healthdirect Australia

Keeping track of periods each month can show a pattern.⁴

Verified with: ACOG, Mayo Clinic

Before a period

Hormone changes before a period can cause physical and emotional changes. This is called PMS (premenstrual syndrome). Typical signs include feeling bloated, breast tenderness, mood swings, feeling irritable, spotty skin, and headaches. They usually get better once the period starts and go away a few days after.⁵

Verified with: NHS, Mayo Clinic, Healthdirect Australia

Pain

More than half of people who have periods get some pain each month. ACOG says it lasts 1 to 2 days, and Cleveland Clinic and Mayo Clinic say 2 to 3. Usually it's mild.¹⁰¹¹¹² It happens because the uterus tightens during a period, and it's often a normal part of the cycle.¹³

Verified with: ACOG, Cleveland Clinic, Mayo Clinic, NHS

It can feel like pain in the tummy just before or at the start of a period, cramps that spread to the back and thighs, or a sharp pain or dull ache. The NHS says it usually lasts up to 3 days.¹³

Verified with: NHS, Mayo Clinic

Things that can help:

• a heat pad, or a hot water bottle wrapped in a towel, on the tummy¹³

  Verified with: NHS, ACOG

• massaging the tummy and back¹³

  Source: NHS, Cleveland Clinic

• gentle exercise like yoga, swimming, walking or cycling¹³

  Verified with: NHS, ACOG

• painkillers like paracetamol (acetaminophen), ibuprofen or naproxen. Always follow the directions on the packet for how much to take.¹³⁴ Ibuprofen and naproxen belong to a group of medicines called NSAIDs. They work best when taken at the first sign of the period or the pain. ACOG says they're usually taken for only 1 or 2 days, and Mayo Clinic says two to three days or until symptoms are gone. ACOG says they aren't for people with bleeding disorders, asthma, an aspirin allergy, liver damage, stomach problems or ulcers.¹⁰¹⁴ The NHS also lists heart or kidney conditions, chickenpox, and being pregnant or trying to get pregnant as reasons to check first.¹⁵ Aspirin isn't for anyone under 16.¹⁶

  Source: ACOG, Mayo Clinic, Cleveland Clinic, NHS

If the pain doesn't go away with these, or it means missing school or normal activities, it's worth talking to a doctor.⁴ If it's worse than usual and painkillers haven't helped, get medical advice urgently.¹³ Severe pain low down, pain that's getting worse or hurts when moving or touching the area, or feeling faint or dizzy, can be an emergency: call the local emergency number or go to an emergency department.¹⁷¹⁸ Sudden, severe pain when pregnancy is possible means going to an emergency room.¹⁹

Source: ACOG, Cleveland Clinic, NHS, Mayo Clinic

Period products

There's no "right" product. Some can be worn together, like a tampon, pad or cup with period underwear for extra protection.⁴

Verified with: ACOG, Mayo Clinic, FDA

Pads

Pads stick inside underwear and soak up the blood. They come in many sizes for heavier or lighter days, and there are reusable washable ones too.⁵ It's best to choose by how heavy the flow is and what feels comfortable. Pads with deodorant may irritate the skin.⁴ Change a pad at least every 4 to 8 hours, or sooner if it feels full, wet or uncomfortable.⁴

Verified with: NHS, FDA, ACOG, Cleveland Clinic

Tampons

A tampon soaks up blood from inside the vagina.⁴ The directions in the box explain how to put one in. Once it's in properly, it shouldn't be felt. A short string hangs out to pull it out later.⁴ If it can be felt or it hurts, it might not be in properly.⁵

Source: ACOG, NHS, FDA

A tampon can't get lost inside the body. The vagina holds it firmly in place, and the cervix is what stops it getting lost.⁵²⁰ It can still get stuck or be forgotten, though. A forgotten one can get lodged at the top of the vagina, next to the cervix. If it can't be taken out easily, see a doctor.²¹

Source: NHS, Healthdirect Australia, Cleveland Clinic

Using tampons safely:

• Wash hands before and after.²²

  Verified with: FDA, Healthdirect Australia

• Change it every 4 to 8 hours, and never leave one tampon in for more than 8 hours.²² On heavier days it may need changing more often.⁴

  Verified with: FDA, Mayo Clinic, Healthdirect Australia, ACOG

• Use the lowest absorbency needed. If one tampon can stay in for 8 hours, it may be too absorbent.²²

  Source: FDA, Mayo Clinic, MedlinePlus

• Only use tampons during a period.²²

  Source: FDA

Menstrual cups

A menstrual cup is made of silicone or rubber and goes inside the vagina. It collects blood instead of soaking it up. It's taken out and emptied every 8 to 12 hours, and many can be washed and used again.⁵⁴ Wash hands, follow the instructions that come with it, and don't leave it in longer than recommended.²³

Verified with: FDA, ACOG, Cleveland Clinic, NHS

Period underwear

Period underwear is made from absorbent fabric that soaks up blood like a pad, with a layer that stops leaks. It's washed and reused.⁵ It can be worn for a full day, though depending on the pair and the flow it may need changing more often.⁴

Source: NHS, ACOG, Healthdirect Australia

Toxic shock syndrome (TSS)

TSS is rare, but it can be life-threatening. It's caused by an infection. It can happen when using a tampon or a menstrual cup. It comes on quickly and needs urgent treatment.²³ Leaving a tampon in for a long time has been linked to TSS.⁴

Verified with: NHS, Mayo Clinic, Cleveland Clinic, ACOG, Healthdirect Australia

Signs can include a sudden fever, throwing up, diarrhoea, fainting or feeling faint when standing up, dizziness, or a rash that looks like sunburn. If any of these happen during or soon after a period, stop using tampons and get medical help straight away.²² Thinking it might be TSS is reason enough to go to an emergency department or call the local emergency number.²⁴²⁵ Take out the tampon or cup, and tell the medical team that one was being used.²³ Call the local emergency number now if there's confusion, slurred speech or not making sense; blue, grey, pale or blotchy skin, lips or tongue; a rash that doesn't fade when a glass is rolled over it; difficulty breathing or breathing very fast; or large areas of peeling skin. Not all of these have to be there.²³

Source: FDA, Cleveland Clinic, MedlinePlus, NHS

When something isn't normal

Having a period shouldn't get in the way of daily life.⁴ The things below are worth checking with a doctor.

Verified with: ACOG, Healthdirect Australia

Very heavy periods

Heavy periods can be normal, and they can be heavier at certain times, like when periods first start.²⁶ Signs a period may be heavy:

Source: NHS, Healthdirect Australia, Mayo Clinic

• a pad or tampon needs changing every 1 to 2 hours, or a cup needs emptying more often than recommended²⁶

  Source: NHS, Healthdirect Australia

• two products are needed at once, like a pad and a tampon²⁶

  Verified with: NHS, Mayo Clinic

• a period lasts more than 7 days²⁶

  Verified with: NHS, Cleveland Clinic

• there are blood clots bigger than about 2.5cm²⁶

  Verified with: NHS, Mayo Clinic, Cleveland Clinic

• blood goes through to clothes or bedding²⁶

  Verified with: NHS, Healthdirect Australia

Needing a new pad or tampon every 1 to 2 hours, or a period that lasts more than 7 days, is a reason to see a doctor.⁴ So are heavy periods that get in the way of life, or that have been going on for some time.²⁶ Feeling light-headed or dizzy, or having a racing pulse, means seeing a doctor right away.⁴ Cleveland Clinic says bleeding through two or more pads or tampons each hour for 2 to 3 hours in a row means seeing a doctor or getting emergency care. Mayo Clinic says soaking through at least one an hour for more than 2 hours means getting medical help before the next scheduled appointment.²⁷²⁸

Source: ACOG, Healthdirect Australia, NHS, Cleveland Clinic, Mayo Clinic

Missing or irregular periods

Late or missed periods have lots of causes. Most of the time it's nothing to worry about, but it's worth seeing a doctor just in case.²⁹ Common causes include pregnancy, stress, sudden weight loss, being overweight, doing too much exercise, and PMOS (more on that below).²⁹ If there's been sex and a period is missed, it's time for a pregnancy test.⁴ If it's positive, here's what comes next.

Source: NHS, Mayo Clinic, ACOG

It's worth checking with a doctor if:

• periods haven't started by 15. Some people don't start until 16 and that can be normal, but it's still worth a check.⁴ The same goes if there are no other signs of puberty by 13.³⁰³¹

  Verified with: ACOG, NHS, Mayo Clinic, Cleveland Clinic, Healthdirect Australia

• periods started but then stopped for more than 3 months⁴

  Verified with: ACOG, Mayo Clinic, NHS

• periods were regular and then became irregular for several months⁴

  Verified with: ACOG, NHS

• a period comes more often than every 21 days, or less often than every 45 days⁴³² (once cycles have settled, about 21 to 35 days apart is usual, so it's fine to ask about longer gaps)⁵⁸

  Verified with: ACOG, NHS, Cleveland Clinic, AAP

• there's bleeding between periods or after sex⁵

  Verified with: NHS, Healthdirect Australia

Pain that keeps getting worse

Sometimes period pain comes from a problem with the reproductive organs. That kind of pain tends to get worse over time and often lasts longer than ordinary cramps.¹⁰ It's worth seeing a doctor if periods get more painful, heavier or irregular, if the pain stops you from doing normal things, if there's pain during sex or when peeing or pooing, or if there's bleeding between periods.¹³

Source: ACOG, Cleveland Clinic, Mayo Clinic, NHS

Signs worth checking: endometriosis

Endometriosis is when cells like the ones lining the uterus grow in other parts of the body. There are treatments that can help.³³ It's often diagnosed from when periods start, and it can affect anyone who has or had a uterus.³³

Source: NHS, WHO

Possible signs include period pain bad enough to stop normal activities, heavy periods, pain low in the tummy and back, pain when pooing or peeing, pain during or after sex, and extreme tiredness.³³ It can take a long time to diagnose, and it might take several different tests.³³

Verified with: NHS, WHO, Mayo Clinic

Signs worth checking: PMOS (PCOS)

The NHS now calls this condition PMOS (polyendocrine metabolic ovarian syndrome). It used to be called PCOS (polycystic ovary syndrome).³⁴ Symptoms usually start at puberty, and it can affect anyone who has ovaries. They can be mild or severe, and some people have none at all.³⁴

Source: NHS, Mayo Clinic

Main signs include irregular periods or long gaps between them, extra hair growth or hair loss, weight gain or finding it hard to lose weight, oily skin and acne, and feeling depressed or anxious.³⁴ These signs are common and can have lots of different causes. Having them doesn't mean someone definitely has PMOS, but it's important to get them checked.³⁴

Verified with: NHS, WHO, Healthdirect Australia

Periods and testosterone

For trans people who take testosterone, periods stopping is a common and wanted effect. In one study, though, some people still had periods more than 6 months after starting.³⁵ If bleeding hasn't stopped after several months, a doctor might suggest medicine to stop it.³⁶ Periods stopping doesn't mean pregnancy can't happen. Testosterone isn't reliable contraception, so anyone who doesn't want to get pregnant should always use birth control.³⁶³⁷

Source: International Journal of Transgender Health, Mayo Clinic, WPATH

More on when to see a doctor and how to ask.

Titles are shown as each source published them, so they may use words this site doesn't.

1. American College of Obstetricians and Gynecologists (ACOG) — Your Changing Body: Puberty in Girls (FAQ) (accessed 2026-10-30)
2. Cleveland Clinic — Menarche (accessed 2026-10-30)
3. NHS — Starting periods (accessed 2026-10-30)
4. American College of Obstetricians and Gynecologists (ACOG) — Your First Period (FAQ) (accessed 2026-10-29)
5. NHS — Periods (accessed 2026-10-30)
6. Healthdirect Australia — Heavy periods (accessed 2026-10-30)
7. Itriyeva, Curr Probl Pediatr Adolesc Health Care 2022 (peer-reviewed) — The normal menstrual cycle (accessed 2026-10-30)
8. Cleveland Clinic — Menstrual Cycle (accessed 2026-10-30)
9. Healthdirect Australia — Menstruation (accessed 2026-10-30)
10. American College of Obstetricians and Gynecologists (ACOG) — Dysmenorrhea: Painful Periods (FAQ) (accessed 2026-10-29)
11. Cleveland Clinic — Dysmenorrhea (accessed 2026-10-30)
12. Mayo Clinic — Menstrual cramps: symptoms and causes (accessed 2026-10-30)
13. NHS — Period pain (accessed 2026-10-29)
14. Mayo Clinic — Menstrual cramps: diagnosis and treatment (accessed 2026-10-30)
15. NHS — Who can and cannot take ibuprofen (accessed 2026-10-30)
16. HSE Ireland — Period pain (accessed 2026-10-30)
17. NHS — Pelvic pain (accessed 2026-10-30)
18. Mayo Clinic — Pelvic pain (accessed 2026-10-30)
19. American College of Obstetricians and Gynecologists (ACOG) — Ectopic Pregnancy (FAQ) (accessed 2026-10-30)
20. Cleveland Clinic — Female Reproductive System (accessed 2026-10-29)
21. Healthdirect Australia — Retained tampon or other object (accessed 2026-10-30)
22. U.S. Food and Drug Administration (FDA) — The Facts on Tampons—and How to Use Them Safely (accessed 2026-10-29)
23. NHS — Toxic shock syndrome (accessed 2026-10-29)
24. Healthdirect Australia — Toxic shock syndrome (accessed 2026-10-30)
25. Cleveland Clinic — Toxic Shock Syndrome (accessed 2026-10-30)
26. NHS — Heavy periods (accessed 2026-10-29)
27. Cleveland Clinic — Menorrhagia (Heavy Menstrual Bleeding) (accessed 2026-10-30)
28. Mayo Clinic — Menorrhagia (heavy menstrual bleeding): symptoms and causes (accessed 2026-10-30)
29. NHS — Stopped or missed periods (accessed 2026-10-29)
30. Mayo Clinic — Amenorrhea: symptoms and causes (accessed 2026-10-30)
31. Healthdirect Australia — Puberty (accessed 2026-10-30)
32. AAP (HealthyChildren.org) — Menstrual Disorders (accessed 2026-10-30)
33. NHS — Endometriosis (accessed 2026-10-29)
34. NHS — Polyendocrine metabolic ovarian syndrome (PMOS) (accessed 2026-10-29)
35. International Journal of Transgender Health (peer-reviewed; Zwickl et al., 2024) — Persistent menstruation in transgender people using testosterone gender-affirming hormone therapy (accessed 2026-10-29)
36. Mayo Clinic — Masculinizing hormone therapy (accessed 2026-10-30)
37. World Professional Association for Transgender Health (WPATH) — Standards of Care for the Health of Transgender and Gender Diverse People, Version 8 (SOC8) (accessed 2026-10-30)