How might an Ovarian Cyst cause problems?
A follicle is normal but when it bursts to release the egg when about 25mm in diameter, there may be a twinge of pain (called mittelschmerz). If it does not burst, there is seldom any trouble until it reaches about 50mm diameter. At this size, the weight of fluid in the cyst causes it to sag down. The pedicle, through which blood reaches the ovary can then twist. Rather like wringing out a towel, this causes pressure in the pedicle. Veins are at lower pressure than arteries and so this twisting (or torsion) can crush the veins, stopping blood leaving the ovary whilst still allowing arterial flow into it. This can cause bleeding into the cyst or rupture.
