Breast pain after open heart surgery is one of the most common and least-discussed complaints among patients recovering from a sternotomy. The discomfort stems from several overlapping causes: the breastbone is physically split and held open, nerves running through the chest wall are stretched or cut, tissues swell with retained fluid, and the hardware used to close the chest can irritate surrounding structures for months afterward. Because breast tissue sits directly over the sternum and relies on the same nerve supply as the chest wall, it absorbs much of this surgical trauma even though the operation itself targets the heart.
What the Sternotomy Does to Your Chest Wall
A median sternotomy, the standard approach for most open heart procedures, involves sawing the breastbone lengthwise from top to bottom. Surgeons then insert a retractor to spread the two halves apart, sometimes quite widely, so they can reach the heart. More than two million people undergo this procedure worldwide each year, and the resulting trauma extends well beyond the bone itself: muscles, cartilage, connective tissue, and the overlying skin and breast tissue are all affected by the force of retraction.
After surgery, the sternum is wired back together, but the surrounding soft tissue needs time to heal. The entire front of the chest becomes a site of inflammation, bruising, and sensitivity. For people with breast tissue, this means the breasts sit on top of a healing wound. Pain in the breast area is often not breast pain in the way most people think of it; it is chest-wall pain radiating outward through tissues that happen to include the breasts. That distinction matters, because the root causes are usually structural and neurological rather than related to the breast tissue itself.
Nerve Damage From the Surgery
One of the biggest contributors to breast and chest pain is damage to the nerves that run along the inside of the rib cage. During coronary artery bypass grafting (CABG), surgeons frequently harvest the internal thoracic artery (also called the internal mammary artery) to use as a bypass graft. This artery runs behind the ribs, and peeling it free inevitably disrupts the small intercostal nerves that branch across the chest wall and supply sensation to the skin, muscles, and breast tissue above.
A study examining patients after internal thoracic artery harvesting found definite nerve damage in roughly three-quarters of subjects, with another 11 percent showing possible nerve damage at the harvesting site. About four in five patients recalled protracted pain or unpleasant sensations in the weeks after surgery, though most of those symptoms subsided within four months. Among patients with confirmed nerve damage, about 15 percent still had persistent pain five to 28 months later.1PubMed. Anterior intercostal nerve damage after coronary artery bypass graft surgery with use of internal thoracic artery graft
The sternal retractor itself is another source of nerve injury. Spreading the chest wide enough for surgical access can stretch or compress the brachial plexus, the network of nerves that runs from the neck through the shoulder and into the arm. Upper rib fractures caused by the retractor can compound this damage.2PubMed. Brachial plexus injury and upper rib fracture after median sternotomy in cardiac surgery Wider retraction and longer time on the heart-lung bypass machine both increase the risk of these injuries. Surgical teams try to limit retraction width and position the retractor carefully, but nerve irritation remains a common trade-off of open heart surgery.3PubMed Central. Does retraction of the sternum during median sternotomy result in brachial plexus injuries?
Altered Sensation and Skin Hypersensitivity
Nerve damage does not always feel like straightforward pain. Many patients experience dysaesthesia, a broad term for abnormal skin sensations like burning, tingling, numbness, or heightened tenderness. A study of post-sternotomy patients found that over half had some form of dysaesthesia, and the affected area was larger in patients who had undergone CABG surgery and in those who reported more severe postoperative pain.4British Journal of Anaesthesia. Dysaesthesia associated with sternotomy for heart surgery
These sensory disturbances frequently extend across the breast area because the intercostal nerves that were damaged supply the skin there. Patients sometimes describe the feeling as if sunburn is under the skin, or report that even light touch from clothing or a bra is uncomfortable. The sensation can come and go unpredictably, which is disorienting. It is not a sign that something new is wrong; it usually reflects the nerves slowly regenerating after injury. That regeneration process, where nerve fibers re-grow and form new connections, can paradoxically create temporary spikes of sensitivity or shooting pains before the nerves settle down.
Fluid Retention and Breast Swelling
Surgical teams administer large volumes of intravenous fluid and blood products during and after heart surgery, and the body’s inflammatory response causes those fluids to leak into surrounding tissues. A large study measuring post-surgical weight gain found that the average patient gained about 5.3 kilograms (nearly 12 pounds) of fluid weight during their hospital stay, and close to 60 percent of patients gained at least 5 percent of their body weight from fluid alone. Women were at roughly double the odds of experiencing this level of fluid retention compared to men.5PubMed Central. Risk of fluid accumulation after cardiac surgery
All that extra fluid has to go somewhere, and breast tissue, which is rich in fatty and glandular tissue with a generous blood supply, tends to swell readily. Swollen breasts become heavier and more tender, which adds mechanical strain on the healing sternotomy incision below. This is the type of breast pain that usually resolves within the first few weeks as the kidneys clear the excess fluid, but it can be quite uncomfortable while it lasts, especially at night when lying flat allows fluid to redistribute.
How Breast Size Affects Recovery
Breast weight is a surprisingly significant factor in how the sternotomy heals. Larger, heavier breasts pull the skin and soft tissue laterally and downward, creating tension across the midline incision. Surgeons have documented cases where this persistent traction contributed to wound dehiscence, a partial or complete separation of the healing sternal wound, in women with very large breasts.6PubMed. Macromastia as a factor in sternal wound dehiscence following cardiac surgery: management combining chest wall reconstruction and reduction mammoplasty
Even when the wound holds together normally, the weight-related pull can translate into pain along the incision, in the breast tissue itself, and in the muscles that are trying to stabilize the healing bone. This is one reason surgical teams often recommend that patients wear a well-fitted sports bra or chest support garment after surgery, though the evidence on whether support bras actually reduce pain is more complicated than you might expect.
Do Support Bras Help?
It seems intuitive that supporting the breasts would relieve strain on the sternotomy and reduce pain. A randomized trial specifically tested this by assigning women undergoing CABG surgery to either wear a support bra during recovery or not. The researchers tracked pain levels during hospitalization and at 30, 60, and 180 days after surgery. Perhaps surprisingly, they found no statistically significant difference in pain frequency or painkiller use between the two groups at any time point.7PubMed Central. Benefits of using a support bra in women undergoing coronary artery bypass graft surgery: A randomized trial
That does not necessarily mean support bras are useless. Many patients report subjective comfort from wearing one, and the trial measured pain frequency rather than every dimension of comfort or wound healing. But the finding does suggest that breast support alone is not enough to meaningfully control post-sternotomy pain, which makes sense when you consider that nerve damage, inflammation, and bone healing are all contributing simultaneously. If a support bra feels better, wear one. Just do not expect it to be a major pain-relief strategy on its own.
Sternal Wires and Lingering Hardware Pain
After the sternotomy, surgeons close the breastbone with stainless steel wires twisted tightly to hold the two halves together. Most patients tolerate these wires without issue, but for some, the wires become a source of chronic pain that can persist or appear months after the surgery seems to have healed. A report on 18 patients with disabling chest wall pain traced the cause to individual sternal wires. The twisted portions of those wires had developed an exaggerated fibrous tissue reaction, and serial tissue sections revealed that sensory nerve fibers had become entrapped in the scar tissue surrounding the wire. Electrical testing confirmed elevated potentials at the damage site, consistent with wire corrosion. Removing the offending wires and the surrounding scar tissue relieved the pain.8PubMed. Delayed chest wall pain due to sternal wire sutures
There is also a separate mechanism: some people are sensitive to nickel, a component of stainless steel. A reported case linked persistent sternal pain to nickel hypersensitivity, and given that nickel allergy is fairly common in the general population, researchers have questioned whether this may explain some cases of post-sternotomy pain that have no other obvious structural cause.9The Annals of Thoracic Surgery. Sternal wire-induced persistent chest pain: A possible hypersensitivity reaction If your breast and chest pain started weeks or months after surgery and seems focused near the incision line, wire-related irritation is worth discussing with your surgeon.
Post-Pericardiotomy Syndrome
Days to weeks after heart surgery, some patients develop a systemic inflammatory reaction called post-pericardiotomy syndrome. The body’s immune system responds to the surgical trauma to the heart and its surrounding sac (the pericardium) by mounting an inflammatory attack, which leads to fluid accumulation around the heart and sometimes the lungs.10PubMed Central. Evaluation and Management of Post-Cardiotomy Syndrome Typical signs include fever, sharp chest pain that worsens with breathing, and elevated inflammatory markers on blood tests.11PubMed. Post-pericardiotomy Syndrome
The chest pain from this syndrome can easily be felt in the breast area, and the pleural effusion (fluid around the lungs) can make it worse when you take a deep breath or lie on one side. This condition is treatable with anti-inflammatory medications such as colchicine or NSAIDs, but it needs to be recognized first. If you develop new chest or breast pain with fever a week or more after surgery, it is worth getting checked rather than assuming it is normal healing.
Fat Necrosis of the Breast
A rarer but understandably alarming complication is fat necrosis in the breast tissue itself. When fatty tissue is traumatized, whether by direct surgical manipulation or by reduced blood supply from harvesting the internal mammary artery, the damaged fat cells can die and form firm, sometimes painful lumps. A case report documented fat necrosis developing months after CABG surgery, presenting with symptoms that initially raised concern for inflammatory breast cancer, including skin changes and a palpable mass.12PubMed Central. Fat Necrosis of the Breast After Coronary Artery Bypass Grafting Presenting Similarly to Inflammatory Breast Cancer
Fat necrosis is benign, but because it can look and feel suspicious on imaging and physical exam, it often triggers biopsies and imaging work-ups before the diagnosis is confirmed. If you notice a new breast lump months after heart surgery, it is absolutely right to get it evaluated, but keep in mind that surgical trauma to the chest is a known cause of fat necrosis and this possibility should be part of the conversation with your doctor.
When Pain Becomes Chronic
Most post-sternotomy breast and chest pain improves significantly within the first three to six months. But for a subset of patients, the pain persists well beyond that window and becomes what researchers call post-sternotomy pain syndrome. This condition involves chronic pain in the front of the chest that can last years or, in some cases, suddenly reappear long after surgery. The exact cause remains unclear, and it likely involves a combination of nerve damage, musculoskeletal changes, and central sensitization, where the nervous system itself becomes amplified in its pain signaling.13PubMed Central. Post-sternotomy pain syndrome following cardiac surgery: case report
The evidence on persistent pain from intercostal nerve damage cited earlier, where about 15 percent of patients with confirmed nerve injury still had pain at five to 28 months, gives a sense of how common this is.1PubMed. Anterior intercostal nerve damage after coronary artery bypass graft surgery with use of internal thoracic artery graft Chronic pain after sternotomy is a recognized medical condition with treatment options, including nerve blocks, targeted physical therapy, medications that calm overactive nerve signaling, and in some cases, removal of sternal wires if hardware irritation is suspected. If your breast or chest pain has not improved after several months, or if it has returned after a period of feeling better, bring it up with your care team rather than assuming it is something you simply have to live with.
Distinguishing Breast Pain From Cardiac Symptoms
One of the more stressful aspects of breast and chest pain after heart surgery is the constant question of whether the pain is “just” from the surgery or whether something is wrong with your heart again. In general, musculoskeletal and nerve-related pain from the sternotomy tends to be positional (worse when you move, twist, cough, or press on the area), localized to specific spots, and often accompanied by the altered skin sensations described earlier. Cardiac pain tends to be deeper, pressure-like, associated with exertion, and sometimes accompanied by shortness of breath, sweating, or nausea.
That said, the overlap can be genuinely confusing, especially in the first few months when everything hurts and you are understandably anxious. A few situations warrant prompt medical evaluation: sudden new pain that feels different from your usual post-surgical discomfort, pain with fever (which could signal infection or post-pericardiotomy syndrome), any wound changes like redness, warmth, or drainage along the incision, and pain accompanied by exertional shortness of breath. Your surgical team would rather see you for a false alarm than miss something real. The threshold for calling should be low in the first year after surgery.