The word menstruation usually refers to menstrual bleeding that occurs once per cycle. A few quick facts about menstruation and menstrual cycle:
- It is not just humans who have menstrual bleeding. Some monkeys, a species of bat and the elephant shrew has a menstrual cycle bleeding.
- Menstruation is the first phase of the menstrual cycle.
- Women get the first menstruation at puberty and menstruation ceases in menopause. The exact age for the last period has a significant variance, but it typically happens when a woman reach 50 years age. The last menstruation or menopause as it is called can occur when a woman is between 45 to 60 years old.
- The biological function of the menstruation is to expel the uterine lining and prepare for a new uterine lining to emerge.
- There is relatively large individual variation how long the menstrual bleeding lasts. Most women have bleeding that last 2 to 7 days. The most common interval is between 3 to 5 days.
- The liquid that is excreted is a mixture of normal blood, bodily fluids and old body tissue. The liquid typically contains between 20 to 80 ml of blood.
- Women who have close contact with each other for a long time can sometimes get their periods in sync with each other. The reason for this is believed to be pheromones, which can be described as airborne organic compounds similar to hormones. It is believed that a form of pheromones are secreted in connection with the menstruation, which in time may affect women that spend a lot of time with each other.
- Pain associated to menstruation is a common but unpleasant symptom. Allergic reactions can worsen during menstruation. Other common symptoms are indigestion, fatigue, irritation and mood swings. Some headache, pain in the back or chest can occur. Your appetite can also be a little bit higher than normal.