Menstrual cycle
What is Menstrual Cycle
The menstrual cycle is a monthly series of changes in the reproductive system that prepares the body for a possible pregnancy. It involves changes in hormone levels, the ovaries, and the uterine lining.
What are the stages of the menstrual cycle?
The menstrual cycle has four main stages:
- Menstruation
- Follicular phase
- Ovulation
- Luteal phase
Changes in reproductive hormones control these stages.
How long does a menstrual cycle last?
A menstrual cycle can vary from person to person. A typical cycle is around 28 days, but cycles between 21 and 35 days can be normal. Count the cycle from the first day of one period to the first day of the next.
What happens during each stage of the menstrual cycle?
- Menstruation: The uterine lining sheds, resulting in menstrual bleeding or a period.
- Follicular phase: Follicles form in the ovary, and the uterine lining begins to thicken.
- Ovulation: An egg is released from the ovary. This is when pregnancy is most likely to occur if sperm are present.
- Luteal phase: Hormones prepare the uterine lining for a possible pregnancy. If pregnancy does not occur, hormone levels fall and the next period begins.
Menstrual cycle vs period
| Menstrual cycle | Period |
| Refers to the entire reproductive cycle. | Refers specifically to menstrual bleeding. |
| Includes menstruation, the follicular phase, ovulation and the luteal phase. | Is the first stage of the menstrual cycle. |
| Usually lasts around 21 to 35 days. | Usually lasts around 3 to 7 days. |
| Begins on the first day of menstrual bleeding and ends before the next period begins. | Occurs when the uterine lining is shed. |
What can affect the menstrual cycle?
Your menstrual cycle can be affected by:
- Stress
- Changes in weight
- Excessive exercise
- Hormonal changes
- Pregnancy
- Menopause and perimenopause
- Some medicines
- Polycystic ovary syndrome (PCOS)
- Thyroid problems
- Some medical conditions
When should you see a doctor about your menstrual cycle?
See your doctor if:
- Your periods are consistently irregular.
- Your periods are abnormally heavy.
- You have severe or ongoing menstrual discomfort.
- Your menstrual cycle shifts suddenly.
- You bleed between periods.
- You have not had a period and could be pregnant.
- Your periods stop unexpectedly.
- Your symptoms are affecting your daily life.
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