The normal length of a woman’s menstrual cycle is 28 days, but this varies between individuals. Irregular menstruation is when the length of the cycle is more than 35 days, or if the duration varies.
A period, or menstruation, is the part of the menstrual cycle in which the endometrium, which is the lining of the uterus, is shed. This appears as bleeding from the womb that is released through the vagina.
Periods usually start during puberty, between the ages of 10 and 16 years, and they continue until menopause, when a woman is 45- to 55-years old.
Irregular periods, also called oligomenorrhea, can occur if there is a change in contraception method, a hormone imbalance, hormonal changes around the time of the menopause, and endurance exercises.
Treatment for irregular periods during puberty and around the menopause is not usually necessary, but if irregular periods occur during the reproductive years, medical advice may be necessary.
In regular menstruation, a woman’s cycle follows a predictable pattern.
A menstrual cycle lasts around 28 days, but it can vary from 24 days to 35 days, depending on the individual.
Most women have between 11 and 13 menstrual periods each year. Bleeding usually lasts around 5 days, but this too can vary, from 2 to 7 days.
When menstruation first starts, it can take up to 2 years to establish a regular cycle. After puberty, most women’s menstruation is regular. The length of time between each period is similar.
However, for some women, the time between periods and the amount of blood shed vary considerably. This is known as irregular menstruation.
The main symptom of irregular menstruation is when the cycle is longer than 35 days, or if it varies in length.
If there are changes in blood flow, or if clots appear that are more than 2.5 centimeters in diameter, this is also considered irregular.
What causes heavy menstrual bleeding?
Heavy menstrual bleeding can also be a problem. Find out more
Irregular periods can sometimes indicate a health problem, and some of these can lead to further problems, such as fertility issues.
Polycystic ovarian syndrome (PCOS) is a condition in which a number of small, fluid-filled sacs known as cysts develop in the ovaries.