Understanding Pain

Pain can be acute or chronic. Acute pain usually has a clear cause that treatment can address, such as a cut on a finger. Chronic pain lasts longer and is more complex, continuing beyond the expected recovery time. It can affect emotional and psychological wellbeing as well as the body. Examples include wounds that do not heal properly and discomfort from long-term illnesses such as cancer and arthritis. Chronic pain can also include mental suffering, for example after the loss of health or of a loved one, or while watching a loved one live with a long-term condition.

Both acute and chronic pain can be neuropathic, visceral, or somatic. Neuropathic pain happens when nerve cells outside the brain and spinal cord are damaged, and it can feel sharp or burning. Visceral pain comes from internal organs such as the stomach, bladder, or chest, and is often deep, dull, cramping, or aching. Somatic pain comes from the skin, muscles, joints, or bones, and is often sharp, throbbing, or a dull ache.

How the nervous system processes pain

The body's response to pain begins with specialised nerve cells called nociceptors. These detect changes in temperature, chemicals, or pressure and send the information towards the brain. The signal travels through the spinal cord with the help of chemical messengers called neurotransmitters.

In the brain, the signal reaches the thalamus, which helps process pain, and is then sent to the relevant brain regions to produce a response. The response may involve movement, such as pulling your hand away from a hot surface. The brain can also release natural pain-relieving chemicals such as endorphins, or it can increase discomfort in the affected area to prompt the immune system to act. Because the brain and body work together to sense and process pain, pain is real. It is not imagined.

Acute pain occurs during the body's first response to injury and usually settles as healing takes place. Sometimes pain signals continue after recovery, and acute pain becomes chronic. Genetic, physical, and psychological factors all influence this change.

People differ in how they experience pain, even within the same household. This variation depends partly on the level of pain-related neurotransmitters released, and studies show that genetic make-up also influences sensitivity to pain. Because the mind and body are involved together, psychological support can be a useful part of managing chronic pain alongside medical care.