Why do ovarian cysts develop?

Written by:

Mr Sandeep Sharma

Obstetrician - gynaecologist

Published: 12/02/2020
Edited by: Laura Burgess


Sometimes, a fluid-filled sac will develop on one of the ovaries, which is known as an ovarian cyst. Most are benign and can clear up on their own without treatment but have you ever wondered why one might occur in the first place and how serious they really are?

We’ve asked one of our expert consultant gynaecologists Mr Sandeep Sharma to answer this question and how they can be detected and treated.

What are the symptoms of ovarian cysts?

Surprisingly, many ovarian cysts produce no symptoms. However, those that grow to a certain size or weight cause symptoms mainly due to pressure on surrounding organs such as the bladder or bowels.

Cysts due to endometriosis can be a cause of constant pain or discomfort. These can also cause pain during intercourse. However, some ovarian cysts can twist and cause acute severe pain requiring emergency surgery.
 

What are the different types of ovarian cysts?

Broadly speaking there are two types, physiological and pathological. Physiological cysts are also called functional cysts and these are seen when the normal ovarian function of ovulation is altered. The importance of knowing this is that these cysts invariably resolve by themselves.

The other type of cysts includes endometriosis and tumours. Endometrial cysts, also called endometriomas are a collection of old blood and need surgery. Tumours, can be benign (non-cancerous) or due to ovarian cancer and always need surgery. Benign tumours can sometimes grow to enormous sizes as they are slow-growing and most women just assume that they are gaining weight.
 

Why do ovarian cysts develop?

The ovaries are very active and undergo physical changes every month due to ovulation. The ovum grows in a bubble called a follicular cyst and if for some reason ovulation is impaired, the cyst keeps growing sometimes to 8 cm in size. After ovulation and sometimes in pregnancy, the residual part of the follicular cyst keeps growing. This is called a luteal cyst.

Endometriosis causes bleeding into the ovary as there is the presence of endometrium (the cells that normally line the inside of the womb) in the ovary. This blood has no place to escape and so it collects within the ovary over months or years, causing cysts in one or both ovaries. Being old blood, it becomes very dark and these are sometimes referred to as chocolate cysts. 

Tumours of the ovary can happen by chance except for about 10% of ovarian cancers that happen more commonly in women with a genetic predisposition. Non-cancerous tumours grow at a slow pace and can grow to very large sizes, sometimes reaching up to the upper abdomen.
 

How can ovarian cysts be detected?

Large cysts are usually palpable on examination but these are always confirmed on an ultrasound scan. This is a simple and non-invasive scan though most women will also need a transvaginal scan to get a complete picture. If there is a doubt regarding the type of cyst an MRI scan is very useful in excluding cancer.
 

How are ovarian cysts treated?

Functional or physiological cysts are usually followed up on an ultrasound scan in 6-8 weeks as the majority resolve with time. However, persistent cysts, endometriosis and tumours need surgery. This is usually achieved through a keyhole (laparoscopic) approach under general anaesthesia.

These operations are done as day cases and depending on the age and fertility needs, usually result in saving the ovary.

Larger cysts can also be managed laparoscopically by expert laparoscopic surgeons, while some women are better suited to have an open operation (laparotomy).


If you have any gynaecological concerns and would like an examination, do not hesitate to book an appointment with Mr Sharma via his Top Doctor’s profile.

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