Most cysts are normal, harmless and functional
“Ovaries are cystic structures – that’s how they work,” says Dr Karen Morton, a consultant gynaecologist and founder of Dr Morton’s medical helpline. “The word ‘cyst’ is just a description for something containing fluid, so depending on what point in the menstrual cycle you’re at, you’d find a cyst on the ovary of varying sizes.”
In menstruating women, the ovaries are full of immature eggs, one of which comes to maturity every month. This happens over the space of about 14 days in a structure called a follicle, before being released for possible fertilisation.
Because the follicle is filled with fluid, it technically counts as a cyst. It will measure around 3cm across by the time it ruptures. Most of the time, the structure disappears without causing any symptoms.
“I am referred so many patients who went to the GP with stomach pain – they’ve been for a scan, and something measuring 3cm was seen on one of the ovaries. 99 times out of 100 it’ll be a normal follicle,” says Dr Morton.