The average period lasts 3 to 7 days, with most people experiencing about 5 days of bleeding. The normal range stretches from 2 to 7 days, and anything within that window is considered healthy. What counts as “your normal” depends on your age, whether you use hormonal birth control, and your individual biology.
What Counts as a Normal Period
Menstrual bleeding typically lasts 2 to 7 days and arrives every 21 to 35 days. The first day or two usually brings the heaviest flow, which then tapers off toward the end. In terms of actual blood loss, a normal period produces less than 60 milliliters of blood, roughly 4 tablespoons. That might feel like more because menstrual fluid also contains tissue from the uterine lining and other fluids, so the total volume on your pad or tampon isn’t pure blood.
Periods between 60 and 100 milliliters of blood loss are considered moderately heavy, and anything over 80 milliliters qualifies as heavy menstrual bleeding. A practical way to gauge this: if you’re soaking through a pad or tampon every hour for several hours, or if your period consistently lasts longer than 7 days, that’s worth bringing up with a healthcare provider.
Why Your Period Happens
Each month, your body builds up the lining of the uterus in preparation for a potential pregnancy. When pregnancy doesn’t occur, levels of estrogen and progesterone drop sharply. That hormonal decline signals the uterine lining to shed, which is the bleeding you experience as your period. Once bleeding ends, usually around day 5, estrogen levels start climbing again and the cycle begins rebuilding the lining for the next round.
How Period Length Changes With Age
Your period doesn’t stay the same throughout your life. In the first year or two after getting a period, cycles are often irregular. The hormonal communication between the brain and ovaries is still calibrating, and many adolescents don’t ovulate during their earliest cycles. It can take a few years for periods to settle into a predictable pattern.
Through your 20s and 30s, periods generally stabilize. Most people in this range can expect a cycle between 21 and 35 days, with bleeding lasting 3 to 7 days. This is the window where you’ll get the best sense of what’s typical for your body.
In the mid- to late 40s, cycles often become irregular again as the body approaches menopause. Cycles may shorten to around 21 days, periods may skip entirely for a month or two, and the flow can become unpredictable, sometimes heavier and sometimes lighter than what you’re used to. This phase, called perimenopause, can last several years before periods stop altogether.
How Birth Control Affects Period Length
Hormonal birth control is one of the biggest factors that can change how long your period lasts, or whether you get one at all.
Hormonal IUDs reduce both the frequency and duration of periods over time. After one year with a higher-dose hormonal IUD, about 20% of users stop getting periods entirely. By the two-year mark, that number climbs to 30% to 50%. Lower-dose versions still shorten periods but are less likely to eliminate them completely.
The injectable contraceptive (given as a shot every three months) has an even more dramatic effect. After one year of use, 50% to 75% of people report no periods at all, and the likelihood increases the longer you use it.
Combination birth control pills can also lighten and shorten periods. The bleeding you get during the placebo week isn’t actually a true period. It’s withdrawal bleeding triggered by the temporary drop in hormones, and it’s typically lighter and shorter than a natural period. Spotting between periods is common in the first few months on any hormonal method but usually decreases as your body adjusts. If breakthrough bleeding stays heavy or lasts more than seven days straight, that’s a reason to check in with your provider.
What Makes a Period Abnormally Long
A period lasting longer than 7 days, or one heavy enough to interfere with daily life, can have several causes. Some of the most common include:
- Uterine fibroids or polyps: noncancerous growths in or on the uterus that can increase bleeding duration and volume
- Hormonal imbalances: conditions like PCOS cause irregular, infrequent periods, but when bleeding does arrive, it often lasts much longer than typical
- Bleeding disorders: conditions like von Willebrand disease affect the blood’s ability to clot, leading to prolonged or heavy periods
- Certain medications: blood thinners and aspirin can extend bleeding
- Pregnancy complications: miscarriage or ectopic pregnancy can cause unexpected heavy bleeding that may be mistaken for a long period
Abnormal uterine bleeding is defined as bleeding that’s unusual in regularity, volume, frequency, or duration. If your periods have changed significantly from what’s been normal for you, or if they consistently fall outside the 2-to-7-day range, that shift itself is useful information. Tracking your cycle length and flow for a few months gives you a baseline, which makes it much easier to spot when something has genuinely changed versus a one-off variation.