Breasts contain milk glands and ducts for transporting milk. These important functional parts of the breast are supported by fatty and fibrous tissues. During the menstrual cycle, menopause, pregnancy and breastfeeding, tissue inside the breast can alter dramatically in size and shape.

Women need to examine their breasts regularly but all breasts can feel lumpy at some time of the month. It is important to learn to recognise what is normal and what is not.

Benign breast lumps are much more common than lumps that are cancerous: 90% of women referred to a breast unit have a breast lump that turns out to be harmless. It is, however, vital to get any breast lumps or changes in breast tissue checked by your doctor so that breast cancer can be ruled out.

Types of benign breast lumps

All breasts are lumpy due to the tissues and structures they contain, but sometimes your breasts can feel different from normal. This can happen because of:

Normal changes caused by fluctuating hormones. This can cause fibrocystic changes or fibroadenosis, which causes temporary benign breast lumps and tenderness.

Infections such as mastitis can occur when ducts become blocked and infected with bacteria that get inside the breast through the cracks in the nipples, causing benign breast lumps to form. Infections are common when breastfeeding but can also affect women who are not breastfeeding. Breast infections are more common in smokers.

Breast cysts, which are fluid-filled sacs within the breast tissue. These are usually caused by changes in hormone levels. They are generally painless but can become sore if they are large. They can also increase in size and tenderness at different times of the month.

Fibroadenomas, which form when glands and connective tissue grow excessively. Fibroadenomas are usually round, firm, rubbery benign breast lumps that move slightly under the fingers and are not usually painful.

Hamartoma, an excess growth of normal breast tissue.

Lipoma, a type of fatty growth found in fatty breast tissue that is usually not painful.

Fat necrosis, a benign breast lump caused by trauma to the fatty tissue in the breast. Sclerosing adenosis, a condition caused by excessive growth of milk-producing tissue. It often causes breast pain because the lumps harden due to calcification.

Papillomas, wart-like benign breast lumps that occur inside a duct behind the nipple. These become increasingly common with age, but can occasionally be linked with atypical hyperplasia. This condition can develop into breast cancer.

Phyllodes tumours are similar to fibroadenomas, and tend to occur in older women. They can be benign, borderline cancerous or malignant.

Should benign breast lumps be removed?

Benign breast lumps often go away without needing any treatment. When they are caused by infection, treatment with antibiotics and/or painkillers is the usual approach. You might also find it eases the pain and soreness if you apply a hot compress.

If they are uncomfortable, other types of benign breast lump can be removed surgically. Papillomas and phyllodes breast lumps are always removed surgically because they can develop into breast cancer.

Benign breast lumps caused by cysts are usually drained by fine needle aspiration under local anaesthetic and do not need surgery. Recurrent cysts might need a small operation and a few stitches and possibly an overnight stay in hospital.