Your menstrual cycle is a monthly hormonal process that prepares your body for possible pregnancy. Understanding it gives you power over your health, your fertility, and your wellbeing.
The average cycle is 28 days, though anywhere from 21 to 35 days is considered normal. It has four distinct phases, each driven by different hormones.
Menstruation begins the cycle. The uterine lining sheds because pregnancy did not occur, and oestrogen and progesterone are at their lowest.
The follicular phase starts as follicle-stimulating hormone prompts the ovaries to develop follicles. Oestrogen rises and thickens the uterine lining.
Ovulation happens when a surge in luteinising hormone releases a mature egg. This is your most fertile window, and the egg lives for about 12 to 24 hours.
The luteal phase follows. Progesterone rises to maintain the uterine lining. If pregnancy does not occur, hormone levels fall and the cycle begins again.
Stress, significant weight changes, illness, travel, and hormonal contraception can all shift cycle length. Tracking your cycle for three to six months gives you a personal baseline.
Speak with a clinician if cycles are consistently under 21 days or over 35 days, bleeding is very heavy, or pain limits normal activity.
