Breast lumps: what causes them?

Breast lumps: what causes them?

Breast lumps can occur for a number of reasons. Sometimes a lump is cancerous, but most breast lumps are benign, or noncancerous.

The breast consists of fatty tissue, which connects to muscles on the chest. It contains glands and ducts that produce and deliver milk to infants. Milk leaves the breast through the nipple.

The breast changes over time. Depending on need, there may be more or fewer milk glands and ducts.

A breast lump can be connect to any of these tissues.

What causes benign breast lumps?

Breast lumps can form from either fatty or glandular breast tissue.

The breasts change throughout the monthly cycle and the life cycle. Pain and lumpiness may occur at some times of the month. If these become troublesome, they are known as a fibrocystic change.

Factors that can lead to breast lumps include fibroadenosis, fibroadenomas, breast cysts, and abscesses.


Symptoms can include:

  • uneven texture or lumps in the breast
  • breast pain
  • swollen breast

The exact cause is unknown, but it may happen when the breast tissue reacts to hormonal changes in the breast due to menstruation.

Fibroadenomas are a common type of breast lump. A fibroadenoma is a smooth, solid lump. It may feel rubbery. This type of lump develops outside the milk ducts in the breast. It happens when the glands and connective tissue overproduce.

These types of lump are sometimes called "breast mice" because they can move around.

They are more likely to affect women under 40 years, and especially those in their 20s.

Fibroadenomas do not disappear after menstruation. During pregnancy, they may become larger. They sometimes go away on their own, and they often disappear after menopause.

Manually self-checking for breast lumps can be the first step to ruling out a more serious complication.

They may result from a reaction to the hormone, estrogen.

Breast abscesses

These are painful lumps that form in the breast. They contain pus. An abscess is a sign of infection.

Other symptoms may include:

  • a fever
  • redness and swelling in the affected area

A breast abscess normally happens because of a bacterial infection. The bacteria can enter through cracks in the skin of the nipple, for example, during breastfeeding.

Breast cysts

Breast cysts are sacs in the breast tissue that fill with fluid. They form smooth, firm, round or oval-shaped lumps.

They are more likely to affect women between the ages of 30 and 60 years, and especially those who are approaching menopause.

Cysts can range in size from very small to over one inch across. There may be only one, there may be several, and they can affect one or both breasts.

As with other breast lumps, it is not clear exactly what causes cysts, but they it may be due to a hormone reaction.

A cyst does not always need treatment, but sometimes a needle aspiration may be done to remove the fluid. However, the cyst can fill up again.

It is not linked to cancer.


This usually occurs when a woman is breastfeeding, but it can happen at other times. It is an infection.

It happens when bacteria enter the milk ducts through cracks in the nipple. The duct can become blocked, and pus builds up in the breast. The breast tissue becomes inflamed and swollen.

If a lump is found, seek medical advice at the earliest opportunity.

Treatment includes warm compresses, pain-killers, and possibly antibiotics.

Other causes

Trauma, such as a blow to the breast, can cause a hard, irregularly shaped lump to form. It usually goes away without intervention.

A lipoma is a fatty growth. It occurs in the fatty breast tissue. Treatment is not usually necessary, but a doctor can remove a lipoma that is large or causes discomfort.

Intraductal papilloma is a growth in the milk duct, rather like a wart.

What causes cancerous breast lumps?

Sometimes, a lump is cancerous. Most cancerous breast lumps are not painful, but between 2 and 7 percent of painful lumps receive a malignant diagnosis.

A malignant breast lump is more likely to:

  • feel firm
  • be clearly defined
  • be fixed in one place
  • be the same at any point during the menstrual cycle
  • develop after menopause

There may also be:

  • nipple discharge
  • dimpling of skin on the breast
  • change in how the nipple looks, for example, a sunken look

Exposure to estrogen during a woman's lifetime may increase the risk of some types of breast cancer.

Mammography scans provide imaging that highlights the nature and development of a breast lump.

Factors that reduce this exposure, such as the onset of menstruation and menopause may affect the risk.

Women who develop breast cancer are more likely to have the following characteristics:

  • being over 50 years of age
  • having a family history of breast cancer
  • having previous diagnosis of breast cancer
  • never having children, or having children after the age of 30 years
  • never having breast-fed a baby
  • menstruation starting at an early age
  • menopause starting after the age of 55 years
  • radiation exposure to the chest
  • use of combined hormone replacement therapy for several years after the age of 50 years
  • high consumption of alcohol
  • having an inherited faulty gene, normally BRCA1 or BRCA2

Studies suggest that the longer a woman has breast-fed, the lower her chance of breast cancer.

This may be because a woman does not ovulate while she is breast-feeding, so her exposure to estrogen is lower.

Breast cancer may be invasive, affecting nearby tissues, or it may be in one location only. It may be fast-growing or slow-growing.

If the cancer is diagnosed when the cells have not spread beyond the duct or lobule where it started, treatment is easier.

Although most breast lumps are not cancerous, any woman who is concerned about a breast lump should seek medical advice.

Breast Lumps – Causes, Types and Treatment (Video Medical And Professional 2020).

Section Issues On Medicine: Women health