Hello,

Thanks for writing to us with your health concern.

A simple cyst is a cyst that is filled with fluid , and hence it appears transparent on ultrasound scan.
Complex cyst is when the cyst contains pus, blood or other solid matter.
Such cysts are less likely to disappear on their own, while simple cysts are generally ones which easily go away .
A complex cyst less than 5 cm is not treated surgically in general, they are observed as they regress quite often.
A complex cyst could be an infectious cyst, which is filled with pus.
It could be a simple cyst inside which bleeding occurred, leading to haemorrhage inside the cyst.
It could be an endometriotic cyst, also called a chocolate cyst, filled with dark brown old blood.
It could be a dermoid cyst, a benign tumour of the ovary.
Malignant growths of the ovary also present as complex cysts.
Generally a cyst that is just 2 - 3 cm, would not have such excruciating pain.
Pain from an ovarian cyst occurs when the cyst is big enough - it would impinge on surrounding structures , nerves or it would twist on itself due to its huge size ( torsion ).
In such a small cyst, you could have had haemorrhage inside the cyst, leading to increased pressure and hence pain.
Also, even a small cyst warrants surgery if it is causing the intractable amount of pain described by you.
CA - 125 is helpful to know if the cyst is likely to be malignant.
Also, at 55, the heavy bleeding is also not normal.
Would you please let me know the status of the uterus and endometrium ( lining of the uterus ) in the ultrasound that was done.
In the appointment you had yesterday, was any medication provided for the pain ?
If not, then yes, you have to see a doctor sooner if the pain is so severe.
If medication was prescribed, then give it a day or two to see if the pain relents.
As the pain is so severe, surgery is a definite option.
It should be a laparoscopic surgery as it is minimally invasive, with less morbidity.

All the best.
Please feel free to ask for any further clarifications.