What Are Breast Cysts?

Have you ever given yourself a breast exam at home due to pain or discomfort and found a lump? Your first instinct would have been to think you found something serious but in most cases, it could be a harmless breast cyst. 

Read on to find out what is a breast cyst, its causes, what symptoms accompany it, and how you can manage and treat it at the right time. 


Breast cysts are fluid-filled round or oval sacs found in one or both breasts varying in size. They are benign (non-cancerous) lumps primarily found in women between the ages of 35-50. They are frequently seen as a lump (or lumps) that are round, moveable, and maybe painful to the touch. Cysts frequently become enlarged, cause unease, and occasionally become more evident right before the menstrual cycle due to monthly hormone fluctuations.1,2

These lumps are caused due to changes in the fibrous tissue in the breast and hence it is collectively called fibrocystic breast changes. These changes are seen in 70-90% of women, and it’sare normal to find breast tissue feeling firm to touch, or a palpable cyst.1,3

Cysts start to form when the fluid inside the breast glands begins to accumulate. They initially appear as microcysts, which are so minute that they cannot be felt unless they are a part of a cluster. They may grow into macrocysts if fluid accumulation persists (large cysts). These are frequently easily felt, and can measure up to one or two inches in diameter.2

Breast Cysts can be of three types such as:1,3

  • Simple cysts: These cysts are completely fluid-filled sacs. They are round or oval-shaped, and the walls of the cyst are smooth. They are typically filled with clear or straw-coloured fluid and are benign (non-cancerous)
  • Complicated cysts: These are similar to simple cysts but have solid fragments called ”debris” floating in the fluid-filled sacs. These cysts are usually benign but the fluid is removed and tested to confirm
  • Complex cysts: These are less common than simple cysts. They have thicker walls and maybe a solid mass. They may also have irregular or irregularly shaped walls. They can be benign or malignant (cancerous) and further diagnostic tests like fine needle aspiration or biopsy may be needed to check the nature of the cyst

Depending on what is discovered after a biopsy, there is a slight possibility that complicated cysts or complex cysts contain cancer cells or increase your risk of developing breast cancer in the future.

Causes of breasts cysts

The exact cause of breast cysts is not very well understood but it is often associated with changes in hormone levels. As the breast develops with age and the levels of the oestrogen (female hormone) fluctuate and cysts may develop. Fluid is created by oestrogen during the menstrual period. Although breast cysts can appear at any age, women over 35 are the ones who are more likely to get them.2,4

Cysts typically stop growing after menopause when oestrogen levels decline. Cysts can still develop in women taking hormone replacement treatment (HRT). Another cause of these cysts is due to blocked breast glands (Milk-producing glands made up of lobules and ducts that carry milk to the nipple). These glands swell up with fluid on occasion causing breast cysts in pregnant or breast-feeding women.4

Though the exact cause of breast cysts is not clear, researchers believe it is a normal and appropriate response to breast growth and development in women with age. Although breast cyst is very common in women, there is still a chance for men to get breast cysts due to genetic changes or obesity.1,2 

Signs and symptoms of breasts cysts

Breast cysts are usually first spotted due to pain and tenderness found in the breast. The signs and symptoms of breast cysts can vary depending on the size and location of the cyst. 

Some common signs and symptoms of breast cysts include:1,2,4

  • A lump or swelling in the breast: This is the most common symptom of a breast cyst. The lump may be round or oval-shaped, and it may move around easily when touched
  • Pain or discomfort: Breast cysts can cause a dull ache or a sharp pain in the breast, particularly during the menstrual cycle. Cycle mastalgia is the term for a rise in breast tenderness and/or pain before menstruation. 20% of breast cysts are accidentally detected in women who experience cyclical mastalgia
  • Tenderness: The breast may become tender to touch, especially around the cyst
  • Nipple discharge: A cyst may cause a clear or milky discharge from the nipple. This could be caused if the fluid from the cyst drains
  • Changes in breast size or shape: A cyst may cause the breast to appear larger or more misshaped

It's important to note that breast cysts can also occur without any symptoms, and they are often found during a routine breast exam or imaging test. If you have any concerns or notice any changes in your breasts, it's important to consult your GP for an appropriate diagnosis as the mentioned symptoms can be caused by other ailments.

Management and treatment for breasts cysts

The management and treatment for breast cysts will depend on the size, location, and symptoms of the cyst, as well as the overall health of the individual. In most cases, the breast cysts will go away on their own, but if they cause discomfort it is best to seek medical help.

 Some standard management and treatment options for breast cysts include:1,2,4

  • Draining the fluid: If the cyst is causing discomfort or pain, your doctor may drain the fluid from the cyst. This can be done using a hollow needle and syringe (fine needle aspiration) or by making a small incision in the breast (surgical aspiration). There is a chance of recurrence of fluid in the cyst sac, hence it must be monitored using ultrasound imaging for 4-6 weeks after aspiration
  • Removing the cyst: If the cyst is large or is causing significant symptoms, it may be removed surgically. This is typically done using a small incision in the breast and is called a cyst excision. This is also done in cases of recurrent breast cysts so they can be tested to see if it is cancerous
  • Medications and home remedies: If you experience pain and breast tenderness before or after aspiration, try taking paracetamol to relieve the pain. In addition, you could use a warm or cold compress to relieve swelling and pain in your breast
  • Monitoring the cyst: If the cyst is small and causing no symptoms, it may be monitored with regular breast exams and imaging tests such as ultrasound or mammogram. If you have been diagnosed with a complex breast cyst your doctor will check the cyst at regular intervals (6-12 months for 2 years) to ensure that it is not growing or changing

Breast cysts may recur or they might even grow in different parts of your breast. Cysts are often treated consistently each time. If you believe your cyst has come back or that you have a new one, you should visit your GP as they might suggest a biopsy to find the nature of the cyst (benign or malignant).


How common are breast cysts?

Breast cysts are quite common, and it is estimated that about 70-90% of women will develop at least one breast cyst at some point in their lives.1

Who usually gets breast cysts?

Women of any age can develop breast cysts, but they are most common in women between the ages of 35-50.1

How are breast cysts diagnosed?

Breast cysts are typically diagnosed through imaging tests, such as ultrasound or mammography. But at times it is detected through a self-breast examination.4

Can I prevent breasts cysts?

There is no known way to prevent breast cysts, but regular breast self-exams and mammograms can help detect them early.4

Are breast cysts cancerous?

Most breast cysts are benign (non-cancerous), but it is important to have any breast lump or change checked by a healthcare professional to rule out cancer. Complex breast cysts are always looked out for as they are concerning. 

When should I call a doctor about breast cysts?

If you notice a lump or change in your breast, or if a breast cyst is causing discomfort or pain, or bloody discharge it is important to contact a healthcare professional for an evaluation.


Breast cysts are fluid-filled round or oval sacs that develop within the breast tissue. They are common, usually benign, and can be caused by hormonal changes or age-included growth of breast tissue. They can be diagnosed through imaging tests and typically treated through fine-needle aspiration or surgical removal. Regular breast self-exams and mammograms can help detect breast cysts early. If you notice a breast lump or change, or if a breast cyst is causing discomfort, it is important to contact your GP for accurate diagnosis and treatment.


  1. Kowalski A, Okoye E. Breast cyst. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022. Available from: http://www.ncbi.nlm.nih.gov/books/NBK562196/ 
  2. Learn all about breast cysts [Internet]. Breast Cancer Now. 2015. Available from: https://breastcancernow.org/information-support/have-i-got-breast-cancer/breast-lumps-other-benign-conditions/breast-cysts 
  3. Fibrocystic changes in the breast | fibrosis and cysts [Internet]. Available from: https://www.cancer.org/cancer/breast-cancer/non-cancerous-breast-conditions/fibrosis-and-simple-cysts-in-the-breast.html 
  4. Breast cysts: what it is, breast cysts symptoms & aspiration [Internet]. Cleveland Clinic. Available from: https://my.clevelandclinic.org/health/diseases/15691-breast-cysts 
This content is purely informational and isn’t medical guidance. It shouldn’t replace professional medical counsel. Always consult your physician regarding treatment risks and benefits. See our editorial standards for more details.

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Jeffy Joseph Vinohar

MSc. Oncology, University of Nottingham, England

Jeffy is an aspiring academic scientist with a bachelors in Biomedical sciences, Biotechnology with a keen interest in cancer studies. During her masters she aimed to learn more about making healthcare accessible and solutions to reduce healthcare inequalities in the field of oncology.
She currently interested in paediatric neuro-oncology and developing less invasive therapeutics for it by obtaining a PhD in coming years, while being involved with simplifying scientific research into health awareness articles.

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