Breast bruising occurs when small blood vessels under the skin leak or rupture. In some cases, pooled blood can develop, damaging larger blood vessels. Here are some of the causes of this condition.

Trauma is a common cause of breast bruising. Sports injuries or falls can lead to bruising or hematomas. These can also form due to weak blood vessels rupturing upon impact. For example, chest injuries from a seatbelt during a motor vehicle accident can cause bruising or minor blood clots. Some severe injuries from strong impacts may require blood transfusions or surgery. Depending on the impact of the injury, bruises are usually flat or swollen and painful, with small blood clots, but some can be as large as an egg, palpable as a lump.

Surgery on the breast can also damage blood vessels and cause bleeding. Examples include surgeries to remove tumors or abnormal breast tissue, cancer, or the entire breast; breast implant and reconstruction surgeries; and breast lifts. Symptoms may also be due to capsular contracture (the process of scar tissue formation that changes the shape of the breast).

A biopsy, a procedure where medical personnel take a breast tissue sample to determine the presence of cancer, can cause bleeding and bruising if not performed correctly. Some types of breast biopsies, such as core needle biopsies, may lead to hematomas, but the rate is low.

Breastfeeding women may experience bruising on their breasts or nipples. This can be due to improper positioning or latching of the baby. Squeezing or expressing milk while breastfeeding can also cause breast bruising.

Some chemotherapy drugs and targeted therapies used to treat cancer can cause bruising as a side effect. If any abnormalities are detected during treatment, patients should consult their doctor for advice on changing methods or medications to limit unwanted side effects.

Bleeding disorders can make individuals more prone to bruising in various locations on the body. Common causes of this condition include von Willebrand disease and inherited bleeding disorders. Platelet disorders, such as Glanzmann's thrombasthenia, can also be a risk factor.

Skin changes on the breast that resemble bruising may be inflammatory breast cancer, although this sign is not common. Inflammatory breast cancer develops rapidly and can cause swelling, redness, pain, and a pink or reddish-purple discoloration of the breast skin.

Minor bruising or hematomas usually do not require treatment and will disappear on their own as the body absorbs the blood. To reduce swelling and pain associated with minor breast injuries, rest and protect the injured area, avoiding strenuous activity. In the first day or two after injury, apply ice packs or cold packs (wrapped in a towel) to the affected area for 10–15 minutes, several times a day.

If bruising lasts longer than two weeks, has an unknown cause, and is accompanied by pain, swelling, or redness, consult a doctor. The doctor may order tests, mammograms, ultrasounds, or biopsies as needed.

Anh Chi (Very Well Health)