Traumatic breast injury can be the result of anything that causes damage to the breast tissue. Typically, side effects are mild. No research suggests breast injury can cause cancer.

The most immediate symptom of a traumatic breast injury is the pain. A traumatic breast injury can cause pain from impact, followed by bruising that may cause aching and discomfort.

It is also possible to experience side effects in addition to bleeding, such as lumps in the breast caused by the injury or the healing process. These lumps may be initially worrisome, but they do not cause cancer.

Woman in a car putting on her seatbelt, which in a crash may cause traumatic breast injuryShare on Pinterest
Some potential causes of trauma to the breast include sports-related injuries, car accidents, and assault.

A frequent cause of traumatic breast injury is a car accident. If a person was wearing a seatbelt, the force of the collision could sometimes cause significant trauma to the chest.

If a person is riding in the front seat and the airbag also deploys, they can experience chest trauma, as a result of the blow from the bag. People can also hit their chest against a steering wheel, dashboard, or front seat when there are no airbags.

Injuries are possible from restraint and safety devices, such as seat belts and airbags, but the injuries are typically less severe than if these devices were not in place.

Other potential causes include assault, a fall, or a sports injury.

Breast injury side effects

Trauma to the breast has the potential to cause severe side effects due to surrounding structures within the breast that can be injured.

Examples include injuries of the blood supply to the breast, such as the branches of the internal mammary artery and of the axillary artery that provides blood flow to the breast tissue.

Injury to the major blood supply to the breast can result in swelling and significant blood loss until treatment is received. More commonly, smaller superficial arteries along with veins become injured, leading to more localized injury and less serious bleeding and bruising.

Some people can experience tearing or direct injury to the mammary ducts, which could affect the future or current flow of breast milk. These are rare, but potential, complications associated with breast trauma.

Most traumatic breast injuries will not result in severe side effects. But it is possible that some people could experience severe complications, such as excessive bleeding due to major blood vessel damage.

Symptoms of severe bleeding can include:

  • feeling faint
  • low blood pressure
  • rapid heart rate
  • shock due to blood loss

These symptoms require emergency treatment and surgery to ensure blood loss due to the injury is stopped.

It is a common misconception that a breast injury could cause cancer. No available research exists that indicates a link between breast injury and cancer.

Some people may believe that a breast injury could lead to cancer because breast injuries can cause a lump to develop after an injury. But a lump could be due to what is called fat necrosis.

Fat necrosis is scarring of dead or injured fatty tissue in the breast that can cause a lump. According to the American Cancer Society, fat necrosis does “not increase a woman’s risk of breast cancer.”

A lump in the breast after an injury can also be due to a deep bruise that is known as a hematoma.

There are several potential complications of a traumatic breast injury:

Fat necrosis

Fat necrosis is a common complication that can occur after an injury to the breast.

Fat necrosis occurs when the body replaces damaged fatty tissue with scar tissue that forms as hard, lump-like areas in the breast.

Oil cyst

Another complication of traumatic breast injury is an oil cyst.

An oil cyst is when the breast cells release an oily substance when the fat cells die, which creates a collection of cells known as oil cysts.

Oil cysts are lumps that may be bruised, red, or thick in texture. Both oil cysts and fat necrosis can cause lumps.


Hematomas are another possible complication and can occur anywhere in the body after an injury, including the breast. Hematomas develop when deeper blood vessels become injured and bleed into the surrounding tissue.

This collection of blood can be firm and create a lump. Hematomas often also result in significant bruising that appears on the skin’s surface.

Treating complications

A doctor may have difficulty telling the difference between breast tumors that are cancerous and lumps due to the side effects of breast trauma.

The first step to evaluating any breast lump is an ultrasound, mammogram, CT or MRI scan.

A doctor may also recommend a biopsy of the tissue in the breast if the images do not provide enough information about the lump. The biopsy allows for a closer look at the breast tissue to ensure the cells are not cancerous.

While fat necrosis or oil cysts can be a complication of the injury, they do not usually require treatment. Bruising and swelling due to fat necrosis or oil cysts should resolve with time. Hematomas that continue to bleed may need draining procedures or surgery for treatment.

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Applying a cloth-covered ice pack to the breasts can reduce swelling.

Rest and time are two of the best healers after a breast injury.

Other tips a person can follow at home to recover from a breast injury include:

  • Applying cloth-covered ice packs to the breasts for 10 to 15 minutes at a time for the first 1–2 days after the injury. This can help to reduce swelling and discomfort.
  • Applying moist heat to areas of hematoma. People can try putting a washcloth in warm (not hot) water, and applying it to injured breast areas. Alternatively, they can try standing under a warm shower.
  • Taking over-the-counter (OTC) anti-inflammatory pain relievers, such as ibuprofen or naproxen. Acetaminophen may help as well. If a person cannot manage their pain with OTC medications, they should talk to their doctor because increased pain could be due to a more severe injury.
  • Wearing a comfortable bra that minimizes movement of the breasts yet is not overly restrictive. Sports bras that have support but no underwire can be a good option.

People can talk to a doctor about removing cysts if an area of fat necrosis or oil cyst continues to cause pain and discomfort.

Although many people can experience a lump in their breast, following an injury, this does not mean they should ignore a new lump. If someone identifies a lump in the breast, they should see a doctor to have it evaluated.

People should also see a doctor if other symptoms occur, including:

  • breast pain that gets worse instead of better with time
  • changes in the skin over the breast, such as thickening, peeling, itching, or redness
  • bleeding or discharge from the nipple
  • signs of infection, such as fever, redness, and warmth of the breast, or drainage from a wound in the breast
  • swelling of the breast that does not decrease

People can ask their doctor when they should expect symptoms to resolve and for any recommendations for further treatments related to the injury.

Traumatic breast injury can be a painful occurrence that can result in side effects, such as breast bruises and cysts. But these symptoms are not cancerous.

With home care and rest, people can usually recover from a traumatic breast injury with minimal complications.