What are breast cysts?

Breast cysts can affect people of all age groups but are most common in women who are approaching the menopause. 

Cysts tend to occur in premenopausal women over the age of 35. They are also common in women who are currently taking hormone replacement therapy (HRT).

In about a third of women who develop breast cysts, lumps are found in both breasts. They can occur suddenly and some women may have more than one breast cyst. Many women may have some form of cysts but do not notice.

What causes breast cysts? 

Breast cysts are caused when breast ducts become expanded and filled with fluid. 

They can change in size at different times of the normal menstrual cycle. They sometimes appear during or after pregnancy due to the filling and emptying of your milk ducts.

They can also occur due to swelling of the fibrous tissue that supports the breasts shape and structure. This can block up the ducts that allow normal secretions to drain away. The extra fluid collects and causes small lumps to form. 

This is a common symptom in many women. They experience feelings of fullness in the upper parts of their breasts. Lumpy areas that may move can feel tender to the touch. 

How are breast cysts treated?

We offer consultation appointments where a doctor can examine any lumps you have found in your breasts. 

They will be able to recommend the next steps and advise on whether further tests are required.

Breasts cysts and breast cancer

Remember that just because you develop breast cysts does not mean that your risk of breast cancer is higher. Family history remains the main breast cancer risk factor.

However, any lump found in the breasts must be checked by a specialist.

If you are prone to breast cysts or other benign lumps, please remain breast aware, and regularly check for any changes.

If you have had breast cysts in the past and you find a new lump, don’t assume it is another cyst. Ensure that it has been properly examined by a doctor for peace of mind.  

What do breast cysts feel like?

Breast cysts are typically oval or round masses that are smooth and moveable under the fingers. They can vary in size from very small and unnoticeable to large and painful.

They may change during the menstrual cycle, with a breast cyst suddenly becoming large and painful just before a period. 

Breast cysts near the surface of the breast tissue usually feel soft, with those found deeper in the breast tissue feeling like hard lumps. They can occur anywhere in the breasts but are most commonly found in the upper half.

Are breast cysts linked to breast cancer?

Breast cysts usually feel quite different from cancer. Benign lumps are usually oval or round, firm or rubbery with smooth edges and are easily moved around under the fingers.

Malignant (cancerous) breast lumps are often hard with a non-uniform shape and irregular edges. They may be fixed to the skin or the chest wall. 

Breast cancer may also be accompanied by other changes such as dimpling of the skin or nipple retraction. These symptoms are not normally associated with breast cysts.

As 90% of malignant tumours are painless, a tender lump is very likely to be a breast cyst or other benign mass.