The exact cause of polycystic ovary syndrome (PCOS) is not known.
It may be linked to:
- insulin resistance
- hormone imbalance
- your ovaries not working properly
Insulin resistance
Insulin is a hormone made by your body. It helps turn glucose (sugar) into energy.
Insulin resistance means your body does not respond to insulin as it should. This causes your body to make extra insulin.
High levels of insulin causes your ovaries to make too much testosterone. This gets in the way of your follicles developing and stops you ovulating normally.
The follicles are sacs in the ovaries where eggs develop.
Hormone imbalance
Many women with PCOS have an imbalance in certain hormones.
Raised levels of testosterone
Testosterone is often considered a male hormone. But all women usually produce small amounts of it.
If you have PCOS, you may make more testosterone than usual.
More testosterone in your body may cause physical symptoms such as excess facial or body hair and acne.
Raised levels of luteinising hormone (LH)
Luteinising hormone (LH) stimulates ovulation.
If LH levels are too high, it can affect your ovaries.
Genetics
PCOS sometimes runs in families. If any relatives, such as your mother, sister or aunt have PCOS, you have a higher chance of having it.
Content supplied by the NHS and adapted for Ireland by the HSE
