The menstrual cycle is regulated by the rise and fall of hormones, and is a natural process whereby the body prepares for pregnancy. About once a month, the uterus grows a new lining (known as endometrium) in preparation for a fertilised egg. In the absence of a fertilised egg, the uterus lining sheds and this leads to the monthly menstruation bleeding. An average menstrual cycle lasts 28 days, but the cycle length and period flow may vary between individuals.
Menstruation usually starts occurring in females aged 11, and typically stops between ages 45 – 60. Menstrual bleeding usually lasts between 3 – 7 days. The end of the last menstrual period is known as menopause. Menstruation is an important part of being healthy. Talk to your gynaecologist if you experience irregular or heavier-than-usual bleeding.
What happens during a menstrual cycle?
The menstrual cycle consists of 3 phases: follicular (before egg release), ovulation (egg release), and luteal (after egg release). The infographic below illustrates the complex interaction of hormones and the changes that occur during a menstrual cycle.
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Follicular phase (Day 1 of bleeding) – The pituitary gland releases a hormone which prompts the development from follicle to egg in the ovary. This releases estrogen which thickens the lining of the uterus in preparation of the possible embedding of the fertilised egg.
Ovulation (Day 14) – A mature egg is released from the ovary. The rise in estrogen leads to a surge in hormones that trigger ovulation where the egg enters the fallopian tube and moves towards the uterus. The egg disintegrates within 24 hours if fertilisation does not occur.
Luteal phase (Day 14 – 28) – The empty follicle collapses after the egg is released and becomes a corpus luteum, which produces the hormone progesterone. This further thickens and nourishes the uterus lining. If fertilisation occurs, the fertilised egg is implanted into the uterus lining and progesterone levels stay high. If no fertilisation occurs, the egg and corpus luteum disintegrates. Estrogen and progesterone levels decline and the menstrual cycle starts again, where the lining of the uterus is shed along with the unfertilised egg.
A regular menstrual cycle is important for a woman’s health and well-being. Certain conditions such as endometriosis may result in painful menstrual cramps or abnormally heavy bleeding. Consult your gynaecologist if you encounter any changes to your menstrual cycle.
Managing menstrual cramps and pain
Most women encounter some pain during menstruation. While period pain is common, in certain instances, the pain may become unbearable and severe enough to affect daily activity. Dysmenorrhoea is the medical term for painful cramps experienced before or during menstruation. Symptoms include:
- Pain in the lower back, hips, or inner thigh area
- Pressure in abdomen
- Pain in abdomen
- Bloating or diarrhoea
- Headache or nausea
- Breast tenderness
Mild menstrual cramps may be relieved by the following methods:
- Place a heat pad on the abdomen
- Take a warm bath
- Have adequate rest
- Exercise regularly
- Avoid caffeine, salt, and alcohol
- Refrain from smoking
Talk to your gynaecologist if you encounter menstrual cramps. Certain medical conditions such as endometriosis may cause period pain. Consult your gynaecologist to find out more.
For more information, download our brochure ‘Painful Periods? It Could be Endometriosis’.
References:
- Proctor M, Farquhar C; Diagnosis and management of dysmenorrhoea. BMJ. 2006 May 13;332(7550):1134-8.
- MedicineNet.com
- Wong CL, Farquhar C, Roberts H, et al; Oral contraceptive pill as treatment for primary dysmenorrhoea. Cochrane Database Syst Rev. 2009 Apr 15;(2):CD002120.