Experiencing unusual nipple discharge is the third-most-common reason women visit their doctors for conditions related to their breasts.
This statistic is according to the Journal of Cellular Immunotherapy, who report that nipple discharge is the third most reported symptom in the breast after breast pain and a lump. Nipple discharge can affect men and women and is not always cause for concern.
Men are also subject to nipple discharge, which is significantly more unusual and requires a doctor’s follow-up.
In women, there are many different potential causes of nipple discharge. One of the most common is a discharge that leaks from a woman’s nipples after she has stopped breast-feeding.
Sometimes, a woman can experience nipple discharge anywhere from 2 to 3 years after she stops breast-feeding.
Additional causes of nipple discharge include:
- abscess (severe breast infection)
- breast infection
- endocrine (hormone) disorder
- excessive nipple stimulation
- fibrocystic (irregular cysts) breasts
- injury or trauma history to the breasts
- mammary duct ectasia (milk duct under the nipple thickens and becomes wide)
- Paget’s disease of the breast (a rare cancer of the nipple and areola)
- periductal mastitis (inflammation)
- prolactinoma (hormone disorder caused by a tumor in the pituitary gland)
- a side effect of taking birth control pills
Some medications can also cause nipple discharge. These include:
Use of the drugs cocaine and marijuana can also cause nipple discharge.
Nipple discharge in men
Men can also experience nipple discharge. Some of the common causes of male nipple discharge include:
- testosterone deficiency
- gynecomastia, a condition that causes breast enlargement or tenderness
- pituitary tumor, this is because the pituitary gland is responsible for releasing hormones that cause milk production in the nipples
- cancer of the breast
Because the condition is much less common in men, a man should see his doctor if he has nipple discharge.
Babies can also experience nipple discharge immediately after birth due to the presence of their mother’s hormones that are still circulating in their bodies. This side effect usually subsides a few days after birth.
To help find the cause, doctors will often ask questions about the discharge, including what color it is and the consistency of the discharge.
Examples of some of the most common types of nipple discharge include:
- Milky discharge: This is the most common type of nipple discharge. In women, this can be because the woman has recently stopped breast-feeding or due to hormonal shifts in a premenopausal woman.
- Bloody discharge: Blood discharge can be caused by a non-cancerous tumor called a papilloma, which can irritate the tissue inside a breast duct. In rare instances, bloody discharge can be due to breast cancer.
- Clear discharge: Clear discharge from one breast only can be a symptom of breast cancer. Clear discharge from both breasts is usually less concerning, but if a woman is concerned, she should visit her doctor.
- Green-tinged nipple discharge: Discharge of this color can be a symptom of a cyst underneath the nipple or areola that is draining.
While each of these discharge types can be alarming, they are not always cause for concern. Bloody and clear discharges are the most common presentations associated with breast cancer.
What are the treatment options?
The treatment options depend on the cause and type of the discharge.
Doctors will diagnose the underlying cause and then treat it, which usually resolves the problem.
Any time a woman experiences nipple discharge that she is concerned about, she should see her doctor. This is especially true if she experiences any of the following symptoms that are associated with breast cancer:
- a palpable lump in the breast
- change in size or shape of the breasts
- discharge from only one breast
- blood-tinged discharge
- discharge that continues over the course of several days
- swelling under the armpit or around the collarbone
A doctor will ask the woman about her symptoms and perform a physical exam. The doctor may recommend imaging studies, such as mammogram or ultrasound, to detect potential abnormalities in the breasts.
Following these diagnostic methods, a doctor may recommend other tests, such as biopsy or blood testing, as indicated.
Nipple discharge can be a symptom of breast cancer, according to the International Journal of Preventive Medicine.
The same journal states that of the women who report nipple discharge of unknown origin, between 7 and 15 percent will have breast cancer.
For the vast majority of women, this means that nipple discharge is not due to cancer. The most common diagnoses for women with cancerous nipple discharge, however, are ductal carcinoma in situ or papillary carcinoma.
If a doctor is unable to establish a clear benign underlying cause for nipple discharge, they will usually recommend an imaging scan to confirm a potentially cancerous lesion is not present. If a person who is at higher risk for breast cancer due to family history experiences nipple discharge, they should speak to their doctor as soon as possible.