How Long Does a Period Last?

What’s Normal and What’s Not for Girls to Older Women

The length of a period varies depending on age—a teenager's period will be different from an older woman’s period. Normal menstruation can last from one to seven days. Most women with regular menstrual cycles have periods that last an average of two to seven days.

Variations in the menstrual cycle are normal and can be caused by factors such as age, birth control, and health conditions like hypothyroidism, polycystic ovary syndrome (PCOS), and more.

Sometimes changes in periods can be a sign of an underlying health issue. And excessive bleeding can lead to anemia (low red blood cells).

This article defines what "normal" menstruation is and the three factors most likely to affect the length of a normal period. It also explains what lengthy and/or heavy periods are and why you should be alert to them.

what affects length of period

​Verywell / Cindy Chung

Normal Menstruation

Your period occurs when the lining of your uterus sheds. Periods are triggered by ovulation, or when an egg is released from an ovary.

Typically, if you don't get pregnant during a cycle, your period will arrive 14 days after you ovulate.

Many women "compare notes" about their periods. But every person is different, and so is their menstrual cycle.

Still, it's not normal to bleed for more than seven days every month or not bleed at all once you have passed menarche, the onset of menstruation during puberty.

Irregularities

A woman's period can vary from cycle to cycle. It is perfectly normal to have a period that is a day or two longer or shorter than usual, as long as it lasts less than seven days.

If a period lasts longer than seven days, but it happens infrequently, it probably isn't something to be concerned about. However, if your cycles regularly last longer than a week, you could be at risk for iron deficiency anemia. Talk to your gynecologist or healthcare provider if your periods last for eight days or longer.

How Age Affects Periods

During the first few years after the start of menstruation, you may experience unpredictable bleeding patterns. The reason? You may not be ovulating regularly yet.

Ovulation requires a complex interaction between your brain, ovaries, and hormones. It can take some time for your body to get the balance right.

After a first period, it will likely be light for the first few menstrual cycles and only last a few days. It's also possible to skip a few periods in a row. Menstruation usually normalizes in about three years.

You may have irregular periods as you approach the end of your reproductive years (at some point in your 40s). This is known as perimenopause, or the menopausal transition.

This is a time when estrogen production begins to decline. As estrogen levels drop, there is less buildup of the uterine lining. Lighter, shorter, and maybe even irregular periods result.

Birth Control

Most women report having lighter and shorter periods when they use birth control. And this goes for both combined hormonal contraceptives—those that deliver both estrogen and progesterone—and progesterone-only contraception.

Lighter, shorter periods happen because the synthetic hormones in birth control override the hormones produced by your ovaries.

Combined hormonal contraceptives include the following:

  • Oral contraceptive pill
  • Contraceptive patch
  • Contraceptive ring

Progesterone-only methods include:

  • Some intrauterine devices (an IUD like Mirena)
  • A contraceptive implant (for example, Nexplanon
  • An injectable contraceptive (like Depo-Provera)

Sometimes women who regularly have heavy or long-lasting periods are prescribed birth control to get their periods under control.

Medical Conditions That Affect Menstruation

Medical issues that change the thickness of the endometrium (uterine lining) or the number of blood vessels within it play a role in how many days your period lasts.

This is because your menstrual flow consists of shedding the endometrium, as well as blood from the little vessels that are exposed afterward.

Heavy and/or long periods could be a sign of:

The thought of some of these conditions may spark fear. See your healthcare provider if you have heavy or long periods, so they can find the cause and treat it.

Long or Heavy Periods

Some women naturally have heavier periods than others, but if your periods are so heavy that they impact your life, you should talk to your healthcare provider.

If you have one long or heavy period, it isn't of concern, but if you have two or more, it shouldn't be ignored. Signs of a heavy period include:

  • Soaking one or more tampons or pads in less than two hours
  • Wearing more than one pad at a time to absorb bleeding
  • Having to change pads or tampons overnight (a time when bleeding often slows)
  • Having periods that include blood clots the size of a quarter or larger
  • Periods last longer than seven days
  • Having to avoid daily activities, like exercise, or take time off work because of your periods
  • Feel tired or short of breath a lot

When to Call Your Healthcare Provider

These are reasons to contact your healthcare provider:

  • Heavy periods are affecting your life.
  • You have heavy bleeding two or more months in a row.
  • You’re bleeding for more days than usual.
  • You have severe pain during your period or when having sex.
  • You have bleeding between periods or after sex.

Summary

"Normal" periods last from one to seven days, with the average lasting between two and seven days. You'll soon find (if you haven't already) that what's normal for you may not be normal for a close friend or family member. So focus on any changes in your own cycle.

Medical conditions, age, and birth control can affect the length and intensity of your period. Heavy or lengthy periods could be a sign of an underlying issue. Take note and call your healthcare provider if you have several heavy or lengthy periods in a row.

5 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. National Health Service UK. Periods and fertility in the menstrual cycle.

  2. Centers for Disease Control and Prevention. Heavy menstrual bleeding.

  3. Santoro N. Perimenopause: From research to practice. J Womens Health (Larchmt). 2016;25(4):332-9. doi:10.1089/jwh.2015.5556

  4. Benson LS, Micks EA. Why stop now? Extended and continuous regiments of combined hormonal contraceptive methods. Obstet Gynecol Clin North Am. 2015;42(4):669-81. doi:10.1016/j.ogc.2015.07.009

  5. National Health Service UK. Heavy periods.

Additional Reading

By Tracee Cornforth
Tracee Cornforth is a freelance writer who covers menstruation, menstrual disorders, and other women's health issues.