Article Date: 09 Feb 2010 – 0:00 PST
Oligomenorrhea is a medical term which generally refers to irregular or infrequent menstrual periods with intervals of more than 35 days – however, the duration may vary.
A period, or menstruation, is the shedding of the endometrium – the lining of the uterus. Menstruation is also called menses. All female humans, as well as a number of other female mammals, have regular periods during their reproductive age. Menstruation, which includes bleeding from the vagina, occurs mainly among humans and similar animals, such as primates. In many mammals, the endometrium is reabsorbed.
As far as humans are concerned a period is a bleed from the womb (uterus) that is released through the vagina. Human females have a period about every 28 days – most women have between 11 and 13 menstrual periods each year. However, some women may have a 24-day cycle while other may have a 35-day one. A period is part of the female’s menstrual cycle.
Periods usually start between the ages of 10 and 16 (during puberty), and continue until the menopause, when woman is 45 to 55 years old. Periods can take up to two years to occur in a regular cycle. After puberty, the majority of females have a regular menstrual cycle (the length of time between each period is similar).
Menstrual bleeding usually lasts for about five days, but can vary from two to seven days.