This section defines the range of normal bleeding patterns. Having a clear understanding of what is considered normal can help you determine if you should be concerned about your menstrual bleeding.

In order to decide whether the bleeding you are experiencing is normal or abnormal, a good starting point is understanding the range of normal bleeding. Learning how to track your periods, get an idea of how much blood loss is occurring, and knowing what to do if your period changes, are all important parts of maintaining menstrual health.

What is a normal period?

There is a range of normal bleeding – some women have short, light periods and others have longer, heavy periods.

Normal menstrual bleeding has the following features:

  • Your period lasts for 3-8 days
  • Your period comes every 21-35 days (measured from the first day of one period to the first day of the next)
  • The total blood loss over the course of the period is around 2-3 tablespoons (30-50 mL)

How much bleeding is too much?

Heavy menstrual bleeding (HMB) is characterized by experiencing any of the following:

  • Bleeding that lasts more than 7 days.
  • Bleeding that soaks through one or more tampons or pads every hour for several hours in a row.
  • Needing to wear more than one pad at a time to control menstrual flow.
  • Needing to change pads or tampons during the night.
  • Menstrual flow with blood clots that are as big as a quarter or larger.

You can learn about the causes of HMB here.

If you are concerned about your menstrual bleeding, or other bleeding tendencies, you can use the self-administered bleeding assessment tool  (Self-BAT) available at the Let’s Talk Period website ( This tool is designed to evaluate menstrual and other bleeding tendencies and tell you if you should be screened for a bleeding disorder.

How can I tell how much blood I am losing?

Measuring the amount of blood lost via menstruation is not that easy, since it is hard to tell how much blood has been absorbed by a pad or tampon. Different products have different absorbencies, and each woman has a different perspective on when a tampon or pad needs to be changed. Using a menstrual cup is one way of getting an accurate measurement of blood loss. Alternatively, you can use this ‘Pictorial Blood Assessment Chart‘ which helps identify whether your blood loss is excessive.

What if my period changes?

Changes in your period can be a sign of a problem, and most changes are worth seeing a doctor about. Some changes that should be investigated include:

  • Your period stops for more than 90 days (and you are not pregnant or on extended regimen birth control)
  • Periods that become irregular when you usually have regular periods
  • Bleeding for longer than normal, for example your period normally lasts 5 days and is suddenly 9 or 10 days long
  • Bleeding between periods, particularly if you are not on any birth control
  • Pain during your period where you have not usually had pain
  • Your bleeding has become very heavy, soaking through more than one pad or tampon per hour or staining night clothes