Lumps on the surface of the breast are relatively common. Luckily, the National Health Service (NHS) in England identifies that up to 85 percent of lumps on the breast are benign. A lump filled with blood may seem to be a cause for concern, but in most cases the reason for this is not serious.
Hormonal changes are the most common cause of lumps on the surface of the breast. This usually refers to menstruation, but hormonal changes during pregnancy and breast-feeding may also cause the lumps. Lumps may also be the result of damage caused by breastfeeding and, in very rare cases, cancer.
If the lump on the breast resembles a fluid-filled bubble on the skin, it may be a blood blister. This occurs when blood vessels just below the skin are damaged, causing blood to flow in between two layers of skin, forming a blister. If the lump is a blister, do not attempt to burst it, because it should drain and heal on its own. As a blood blister on the breast will most likely have been caused by wearing a bra, try not to wear a bra until it heals. If this is not possible, avoid the bra that caused the blister until it heals.
A cyst is a lump that is filled with fluid, sometimes blood. Cysts are usually benign lumps and, according to the NHS, are most common in premenopausal women between the ages of 40 and 45 and women taking hormone replacement therapy. Cysts are usually caused by a clogged gland or an infection and can occur within the breast or on the skin. Generally, a cyst can be lanced and drained.
If you have a lump in your breast and are experiencing bloody discharge from the nipple, you may have a cyst. In rare cases, a blood-filled lump within the breast may be caused by a tumor. A non-cancerous tumor in the milk ducts may cause bloody discharge. According to the MERCK Medical Online Library, less than 10 percent of cases are caused by cancer. Breast cancer can be life-threatening, and immediate treatment is recommended.
When a lump is found in the breast, there is always a chance of cancer. Because of this, you should always consult a doctor as soon as possible after you find a lump. It is very uncommon that a blood-filled lump on the surface of the breast will be cancerous, but such a lump should still be checked out by a doctor.