Periodos
Periods: what to expect
Revisado: 4 de octubre de 2026
Solo en inglés por ahoraA period is when your body sheds the lining of the womb. Here is how long periods usually last, how much blood is typical and how periods change through life.
What a period is
Each month, the lining of your womb (uterus) builds up. During a period, your body sheds this lining. The lining comes away as blood and tissue. It passes through the cervix (the neck of the womb) and leaves your body through the vagina. This bleeding is your period. The first day of bleeding is also the first day of a new menstrual cycle.
How long it lasts and how often
A period usually lasts about 5 days, but anything from 2 to 7 days is common. Your cycle is the time from the first day of one period to the start of the next. Many people have a period about every 28 days, but it is common to have them more or less often than this. Most adult cycles last somewhere between about 21 and 38 days. A cycle can also be a bit shorter or longer from one month to the next.
How much blood is normal
Most people lose about 20 to 90 ml of blood in a whole period, which is roughly 1 to 5 tablespoons. On average, it is about 2 to 3 tablespoons. Some people bleed more than this. The amount usually changes over the days of a period, and it can differ from month to month. Blood is usually red when the flow is heaviest. On lighter days it may look pink or brown.
How periods change through life
On average, a first period comes at about age 12, but starting any time from 8 to 15 is within the usual range. For a few years after the first period, cycles are often irregular, and cycles longer than 38 days are common. Periods also tend to be heavier in the teenage years. In your 20s and 30s, cycles are usually more regular. In your 40s, as your body moves towards menopause, cycles may become irregular. Periods can stop for a month or a few months and then start again. Menopause usually happens between the mid-40s and mid-50s.
When to talk to a doctor or nurse
Logging your periods in Ciclo can help you notice changes. Talk to a doctor or nurse if your cycles are often shorter than 24 days or longer than 38 days. Also talk to them if you have had no period for 3 months and are not pregnant or breastfeeding. Get checked too if a first period comes before age 8, has not come by 15, or has not come within 3 years of breast growth. If pain or bleeding stops you going to school or work, or doing things you usually do, get help, because it can be treated. Bleeding between periods, after sex or after menopause should always be checked by a doctor or nurse.
When to get urgent help
Also see a doctor or nurse if you need to change a pad or tampon every 1 to 2 hours, or if your period lasts more than 7 days. Call your local emergency number or go to an emergency department if you are bleeding heavily and you faint or feel about to faint, or you have chest pain or trouble breathing. If heavy bleeding makes you feel dizzy, light-headed or weak, contact a doctor or nurse the same day. Get emergency help for sudden, severe pain in your tummy.
This is general information, not a diagnosis. If your periods change or worry you, talk to a doctor or nurse.