Pain after surgery may persist for months or even a year after the surgery.

The lump, tumour or diseased part of the organ is long gone, but pain still persists three to six months after surgery and sometimes, even after a year. Chronic post-surgical pain is not uncommon. Knowing the causes of pain is important in getting the right treatment.

“Post-surgical pain is normal and starts immediately after surgery or within the first few weeks. Chronic post-surgical pain is continuous or intermittent pain that persists for months after the operation, beyond the expected healing period,” says Dr Tan Kian Hian, Senior Consultant, Department of Anaesthesiology and Director, Pain Management Centre, Singapore General Hospital (SGH), a member of the SingHealth​ group.

Causes of chronic post-surgical pain

The first step in effective pain management is to rule out non surgery-related causes of pain such as cancer and pre-existing illnesses, as well as other potential complications of the surgery which may account for the pain, adds Dr Tan.

Certain surgical procedures are more likely to cause chronic post-surgical pain. These include breast removal due to breast cancer (mastectomy), removal of lymph nodes (axillary dissection), chest surgery (thoracotomy), hysterectomy, hernia surgery and limb amputation.

Some patients may experience phantom pain, which is pain felt in a body part that’s no longer there.

Persistent inflammation at the surgical site and peripheral nerve damage as a result of surgery (neuropathic pain) may lead to chronic post-surgical pain. In chest surgery for example, the surgeon has to open up the rib cage or part of a rib and this may affect the intercostal nerves along the ribs, thus causing pain.

Patients with significant preoperative pain have a higher risk of developing chronic post-surgical pain. They may be hypersensitive to pain and touch due to a condition called central sensitisation in which their central nervous system has developed a heightened response to pain.

Read on to learn about ​ treatments and prevention for chronic post-surgical pain​. ​​

Ref: R14