Periods bleed because of a natural process in the female reproductive cycle.
The Menstrual Cycle Explained
Here's a breakdown of why menstruation occurs, based on the provided reference:
- Hormonal Preparation: The ovaries release estrogen and progesterone. These hormones cause the lining of the uterus (also known as the womb) to thicken.
- Think of this as preparing a soft, nutrient-rich bed.
- This built-up lining is designed to support a fertilized egg if one is present.
- No Fertilized Egg: If a fertilized egg (an egg joined with sperm) doesn't implant in the uterus, the body recognizes that pregnancy hasn't occurred.
- Lining Breakdown: Without a fertilized egg, the built-up uterine lining is no longer needed. Therefore, the lining breaks down.
- This is a natural shedding process.
- Bleeding: The breakdown of the uterine lining results in bleeding, which is what we experience as a menstrual period.
| Phase | Event | Hormone Influence | Result |
|---|---|---|---|
| Proliferative Phase | Uterine lining thickens | Estrogen & Progesterone | Preparation for fertilized egg implantation |
| Luteal Phase | No fertilized egg, lining is unneeded | Drop in hormones | Uterine lining sheds, causing bleeding |
In Summary
Menstrual bleeding is a result of the body preparing for potential pregnancy. If fertilization does not occur, the body sheds the thickened uterine lining, which causes menstruation. This monthly cycle ensures the body is prepared for the possibility of a fertilized egg, or if not, removes the unneeded lining.
