Other Ways Pain Is Classified
Pain is most often classified by the kind of damage that causes it. The two main categories are pain caused by tissue damage, also called nociceptive pain, and pain caused by nerve damage, also called neuropathic pain. A third category is psychogenic pain, which is pain that is affected by psychological factors. Psychogenic pain most often has a physical origin either in tissue damage or nerve damage, but the pain caused by that damage is increased or prolonged by such factors as fear, depression, stress, or anxiety. In some cases, pain originates from a psychological condition.
Pain is also classified by the type of tissue that's involved or by the part of the body that's affected. For example, pain may be referred to as muscular pain or joint pain. Or a doctor may ask you about chest pain or back pain.
Certain types of pain are referred to as syndromes. For instance, myofascial pain syndrome refers to pain that is set off by trigger points located in the body's muscles. Fibromyalgia is an example.
Pain Caused by Tissue Damage
Most pain comes from tissue damage. The pain stems from an injury to the body's tissues. The injury can be to bone, soft tissue, or organs. The injury to body tissue can come from a disease such as cancer. Or it can come from physical injury such as a cut or a broken bone.
The pain you experience may be an ache, a sharp stabbing, or a throbbing. It could come and go, or it could be constant. You may feel the pain worsen when you move or laugh. Sometimes, breathing deeply can intensify it.
Pain from tissue damage can be acute. For example, sports injuries like a sprained ankle or turf toe are often the result of damage to soft tissue. Or it can be chronic, such as arthritis or chronic headaches. And certain medical treatments, such as radiation for cancer, can also cause tissue damage that results in pain.
Pain Caused by Nerve Damage
Nerves function like electric cables transmitting signals, including pain signals, to and from the brain. Damage to nerves can interfere with the way those signals are transmitted and cause pain signals that are abnormal. For instance, you may feel a burning sensation even though no heat is being applied to the area that burns.
Nerves can be damaged by diseases such as diabetes, or they can be damaged by trauma. Certain chemotherapy drugs may cause nerve damage. Nerves can also be damaged as a result of stroke or an HIV infection, among other causes. The pain that comes from nerve damage could be the result of damage to the central nervous system (CNS), which includes the brain and spinal cord. Or it could result from damage to peripheral nerves, those nerves in the rest of the body that send signals to the CNS.