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.