The causes and treatment of breast discharge


Although discharge of fluid from the nipple is usually due to hormone-related benign conditions it can also be a symptom of breast cancer. This article outlines the possible causes of breast discharge and explains how the cause is diagnosed and treated.


Types of nipple discharge

Nipple discharge is the production of fluid from the nipple. The fluid comes from the milk gland ducts that open at the nipple. Although the average number of milk ducts opening on the surface of the nipple is 27, only five of these ducts are functional.

Most cases of nipple discharge are due to normal, benign conditions and are usually hormone-related. Approximately one third of all women can produce a nipple discharge by gently massaging their breasts. This 'innocent' nipple discharge usually comes from multiple ducts in both breasts in pre-menopausal women. Blood-stained discharge from a single duct in one breast can be sinister in nature and may represent an underlying carcinoma.

What do I do if I have nipple discharge?

Women with nipple discharge should consult their GP without delay. They may then be referred to a breast specialist who will examine the breasts in more detail.

Management of nipple discharge

Depending on the number of discharging ducts and the colour of the discharge produced, the specialist may arrange further investigations including microscopic examination of the discharge fluid, an ultrasound scan (if the patient is younger than 35 years) and/or a mammogram (if the patient is older than 35 years). Occasionally a breast lump is found in a patient presenting with nipple discharge. Such lumps are investigated appropriately.

If the microscopic examination and mammography/ultrasound show no worrying features, the patient can be reassured. Women who have blood-stained discharge coming from a single milk gland duct, and show abnormalities on microscopic examination, will require surgical excision of the discharging duct. The operation to remove a single duct is known as a microdochectomy and is usually performed as a day-case procedure. The removed tissue is sent to the pathology laboratory for further examination. In some centres it is also possible to carry out a camera examination of the nipple duct, which is called mammary ductoscopy. I introduced this new technology to the UK 10 years ago. Figures 1 and 2 show the endoscopy of a normal milk duct and one exhibiting early breast cancer resulting in nipple discharge.

Clear discharge arising from multiple milk gland ducts is usually normal. It does not require treatment unless it becomes troublesome or associated with abnormal microscopy or mammography, when surgery may be considered. The operation consists of the total removal of all the ducts draining into the nipple. The main risks of the procedure include the death of the nipple tissue (uncommon) and the reduced sensitivity of the nipple area (one third of cases). Such complications should be weighed against the severity and inconvenience of the symptoms.

What does a milky discharge mean?

Milky discharge through the nipple, called galactorrhoea, is normal during and within two years of pregnancy. Milky discharge occurring outside pregnancy can be caused by an imbalance of the hormone prolactin, which controls milk production. A small gland in the brain, called the pituitary gland, produces prolactin. Tumours arising in this gland may cause excessive amounts of prolactin to be released into the bloodstream, thus stimulating the breast tissue to release a milky discharge. A brain scan may be required to look for tumours in the pituitary gland. Pituitary tumours are usually benign and are easily treated with drugs or through surgery. If prolactin levels are within normal limits, the patient can be reassured that the discharge is likely to improve without further intervention.

Causes of nipple discharge

  • Inflammation e.g. periductal mastitis
    • Pain and nipple inversion are common
    • It is more common in smokers
    • It can be improved through stopping smoking and taking antibiotics
    • Surgery may be required if persistent
  • Duct ectasia: dilation of the nipple duct
  • Intraductal papilloma: Benign tumour of the nipple duct
    • Usually causes a single-duct blood-stained discharge
    • Can be treated by surgical removal of the papilloma
  • Breast cancer
    • Non-invasive (DCIS) type may cause blood-stained nipple discharge. This type of cancer does not usually spread. Mastectomy (with/without immediate reconstruction) is usually required as it is close to the nipple. Surgical treatment can cure 98% of cases.

Breast ductoscopy

Click on the link below for images of breast ductoscopy under local anaesthesia (as performed by Prof Kefah Mokbel).

Please note that you must be over 18 to view these images.

For further information on the author of this article, Consultant Breast Surgeon, Professor Kefah Mokbel, please click here.
Medication to treat infections caused by microbes (organisms that can't be seen with the naked eye), such as bacteria. Full medical glossary
Not dangerous, usually applied to a tumour that is not malignant. Full medical glossary
A fluid that transports oxygen and other substances through the body, made up of blood cells suspended in a liquid. Full medical glossary
Abnormal, uncontrolled cell division resulting in a malignant tumour that may invade surrounding tissues or spread to distant parts of the body. Full medical glossary
A malignant tumour (cancer) that is formed from the epithelium, the tissue that covers the open surfaces of organs. Full medical glossary
A condition that is linked to, or is a consequence of, another disease or procedure. Full medical glossary
Examination of the inside of the body using a tube equipped with a light source and either a small camera or an optical system. Full medical glossary
The removal of a piece of tissue or an organ from the body. Full medical glossary
A viral infection affecting the respiratory system. Full medical glossary
An organ with the ability to make and secrete certain fluids. Full medical glossary
A substance produced by a gland in one part of the body and carried by the blood to the organs or tissues where it has an effect. Full medical glossary
An imaging study of the breasts, for example, by X-ray. Full medical glossary
A diagnostic and screening test using low-dose X-rays to detect breast tumours Full medical glossary
Infection of the breast tissue, most often affecting breastfeeding women Full medical glossary
Relating to the menopause, the time of a woman’s life when her ovaries stop releasing an egg (ovum) on a monthly cycle. Full medical glossary
The use of microscopes to investigate objects too small to be seen with the naked eye. Full medical glossary
A non-cancerous growth that resembles a wart. Full medical glossary
When the ducts underneath the nipple become inflamed and infected. Full medical glossary
A gland deep in the brain that produces several hormones controlling the production of other hormones throughout the body Full medical glossary
the period from conception to birth Full medical glossary
A hormone produced by the pituitary gland in the brain that stimulates breast growth and milk production. Both men and women produce some prolactin, but levels increase in women during pregnancy and breastfeeding Full medical glossary
A tube placed inside a tubular structure in the body, to keep it patent, that is, open. Full medical glossary
A group of cells with a similar structure and a specialised function. Full medical glossary
An abnormal swelling. Full medical glossary
A diagnostic method in which very high frequency sound waves are passed into the body and the reflective echoes analysed to build a picture of the internal organs – or of the foetus in the uterus. Full medical glossary