Intercostal neuralgia is caused by damage, compression, or irritation of the intercostal nerves that run along the underside of each rib. The most common triggers are chest surgery, rib fractures, and shingles infections, though the list of possible causes is long and sometimes surprising. The pain is neuropathic, meaning it originates from the nerve itself rather than from inflamed tissue or muscle strain, which is why it often feels like burning, stabbing, or electric shocks that wrap around one side of the chest wall.
How the Intercostal Nerves Get Damaged
Twelve pairs of intercostal nerves branch off the spinal cord in the thoracic region and travel forward between the ribs, supplying sensation to the skin, muscles, and lining of the chest and upper abdomen. Because these nerves sit in narrow grooves along the bottom edge of each rib, they’re vulnerable to anything that squeezes, stretches, or cuts into that space. Once injured, a nerve can form scar tissue or a small tangle of nerve fibers called a neuroma, both of which generate abnormal pain signals long after the original injury has healed.
The damage can be sudden, like a fractured rib slicing into the nerve, or gradual, like a slowly growing mass pressing against it over months. It can also be chemical or inflammatory, as when a virus attacks the nerve from within. The common thread across all causes is that something disrupts normal nerve signaling, leaving behind a nerve that fires pain signals on its own or in response to light touch that shouldn’t hurt.
Surgery and Medical Procedures
Surgical trauma is one of the most frequently documented causes. Any operation that requires cutting between or spreading the ribs can injure intercostal nerves directly. Thoracotomy (opening the chest wall for lung or heart surgery) is a well-known culprit because surgeons must retract the ribs apart, stretching or crushing the nerve in the process. The resulting chronic pain, sometimes called post-thoracotomy pain syndrome, can persist for months or years after the incision has fully healed.
Mastectomy and other breast surgeries carry a similar risk because incisions and tissue removal can sever small nerve branches in the chest wall. Even less invasive procedures matter: chest tube placement, for instance, involves pushing a tube between two ribs, and that insertion point can leave behind nerve damage. Surgical retraction of any kind, where instruments hold tissue apart to give the surgeon a view, can stretch intercostal nerves beyond their tolerance and cause a temporary or permanent conduction injury.
Rib Fractures and Chest Trauma
A broken rib is one of the more straightforward paths to intercostal neuralgia. As the fracture heals, the body lays down a bony callus around the break site. If that callus forms excessively or in the wrong direction, it can physically trap the intercostal nerve running just beneath the rib. In one documented case, a patient with a sixth rib fracture developed a malunion with excessive callus that completely entrapped the nerve, causing refractory pain that didn’t respond to standard painkillers.
The timing is a useful clue. Acute rib fracture pain typically improves over several weeks as the bone knits together. When pain instead shifts from a dull ache to something sharper, more burning, or more electric, and follows a band-like pattern around the chest, intercostal neuralgia is likely. Pain that persists in this pattern beyond six months after a chest injury strongly suggests nerve involvement rather than ongoing bone or muscle healing. Blunt force trauma to the chest, even without a clear fracture on imaging, can also bruise or stretch these nerves enough to cause lasting symptoms.
Shingles and Post-Herpetic Neuralgia
The varicella-zoster virus, the same one that causes chickenpox, can reactivate decades later as shingles. It lives dormant in nerve cell clusters near the spine, and when it flares, it often travels down an intercostal nerve, causing a painful blistering rash in a belt-like strip across one side of the chest. The virus damages the nerve directly as it replicates inside nerve fibers.
For most people, the rash and acute pain resolve within a few weeks. But in some cases, the nerve damage is severe enough to cause chronic pain that outlasts the rash by months or even years. This is called post-herpetic neuralgia, and it’s one of the most common causes of long-term intercostal nerve pain. Patients typically describe shooting, burning, and aching pain in the area supplied by the affected nerve, often beginning one to three months after the initial shingles outbreak. The risk increases with age, which is one reason the shingles vaccine is recommended for older adults.
Pregnancy
Intercostal neuralgia during pregnancy has two overlapping causes. The first is mechanical: as the uterus grows, it pushes upward against the diaphragm and increases pressure inside the abdomen. This displaces the lower ribs and stretches the intercostal nerves beyond their normal range. Coughing or minor local trauma can make it worse because the nerves are already under tension.
The second factor is hormonal. Progesterone and relaxin, both elevated during pregnancy, loosen ligaments and increase the mobility of the joints where the ribs connect to the spine. That extra movement creates unusual pressure on nerves that are accustomed to a more stable bony framework. The combination of a heavier abdomen pulling the rib cage outward and loosened joints allowing more rib movement makes the third trimester a particularly common time for symptoms to appear. The good news is that pregnancy-related intercostal neuralgia usually resolves after delivery as the mechanical and hormonal pressures reverse.
Tumors and Growths
Tumors growing along or near intercostal nerves can compress them slowly enough that pain develops gradually over weeks or months. Schwannomas, a type of benign nerve sheath tumor arising from the cells that insulate nerves, are the most common nerve-specific tumors in this area, though they’re still considered rare. Most present as slow-growing, painless masses and are discovered incidentally on chest imaging done for other reasons. When they do cause pain, it follows the path of the affected intercostal nerve.
Malignant tumors are less common but more aggressive. Malignant peripheral nerve sheath tumors tend to compress or destroy adjacent structures and may show abnormalities on the lining of the lung. Tumors originating elsewhere, such as lung cancer or metastases to the spine or ribs, can also invade or compress intercostal nerves as they grow. Any new, unexplained band-like chest pain that worsens over time warrants imaging to rule out a mass.
Other Contributing Factors
Several less obvious conditions can set the stage for intercostal neuralgia. Obesity and ascites (fluid buildup in the abdomen) increase intra-abdominal pressure in much the same way pregnancy does, stretching the lower intercostal nerves. Chronic, forceful coughing from conditions like COPD or severe respiratory infections creates repetitive tension on the nerves with each cough cycle, sometimes enough to cause lasting irritation.
Nutritional deficiencies also play a role. Vitamin B12 is essential for maintaining the protective myelin coating around nerves. When B12 levels drop, nerves lose insulation and begin firing abnormally, which can contribute to neuropathic pain in the intercostal region and elsewhere. There is some clinical evidence that B12 supplementation can help with post-herpetic neuralgia specifically, likely by supporting nerve repair and reducing abnormal nerve firing.
Autoimmune and inflammatory conditions can attack nerve tissue directly, though this is a less common pathway. Metabolic disorders, particularly diabetes, cause widespread nerve damage that can include the intercostal nerves, though it more commonly affects the hands and feet first. In some cases, no clear cause is ever identified. The nerve pain appears without a preceding injury, infection, or visible structural problem, which can make diagnosis frustrating but doesn’t change the treatment approach.
Why the Pain Feels the Way It Does
Intercostal neuralgia produces a distinctive pattern because the nerve follows a predictable path. Pain typically wraps from the spine around one side of the chest toward the breastbone, tracing the course of a single nerve or sometimes two adjacent ones. It’s often described as burning, stabbing, or shooting, and it can be triggered or worsened by deep breathing, twisting, coughing, laughing, or even light touch on the skin over the affected area.
This sensitivity to light touch, where even clothing brushing against the skin causes pain, happens because the damaged nerve has become hyperexcitable. Normal sensory signals that should register as gentle pressure get amplified into pain signals. The band-like distribution and neuropathic quality of the pain are what distinguish intercostal neuralgia from muscle strains, costochondritis, or cardiac pain, all of which can also cause chest discomfort but with different patterns and characteristics.