The cause of chronic pain is not clear. When you have an injury or illness, certain nerves send pain signals to your brain. With chronic pain, these pain signals continue for weeks, months, or even years after you recover. Chronic pain can develop after a major injury or illness, such as a back injury or shingles, or it can develop without a known cause. It is also possible that certain brain chemicals that usually suppress pain may not work properly. The pain may be:
Neurogenic pain, or neuropathic pain, which occurs when the peripheral nerves or central nervous system are somehow damaged. The nerves themselves cause the pain, and this kind of pain may not respond well to treatment.
Psychogenic pain, which is pain that may be caused by an emotional or mental health issue. This pain is not caused by a disease, injury, or damage to the nervous system. Psychogenic pain is not common, but stress, depression, and other mental health factors can make the pain worse.
Unidentifiable pain. It may be impossible to find or identify the cause of your pain. Tests may not reveal any injury, illness, or tissue change that could have triggered the pain.
The symptoms of chronic pain include:
Pain that does not go away as expected after an illness or injury.
Pain that may be described as shooting, burning, aching, or electrical.
Discomfort, soreness, tightness, or stiffness.
Pain can lead to other problems, such as:
Fatigue, which can cause impatience and a loss of motivation.
Sleeplessness, often because the pain keeps you awake during the night.
Withdrawal from activity and an increased need to rest.
A weakened immune system, leading to frequent infections or illness.
Depression, which is common and can make your pain worse.
Other mood changes, such as hopelessness, fear, irritability, anxiety, and stress.
Disability, which may include not being able to go to work or school or perform other daily activities.
Exams and Tests
Many exams and tests are used to evaluate chronic pain. The first assessment includes:
A detailed medical history. Your doctor will ask you about your general medical history, past illnesses, and overall health. He or she will ask you questions about your pain, previous pain episodes, how they were treated, and whether treatment was successful. Also, your doctor will note any family history of chronic pain. In order to identify activities that cause pain, how you treat pain when it occurs, and whether the treatment relieves the pain, your doctor may ask you to start keeping a pain diary (What is a PDF document?) .
A physical exam. Your physical well-being will be evaluated, which will help your doctor identify areas of pain. You may be asked to move your limbs to help identify painful areas. A physical exam may uncover health conditions that contribute to chronic pain. As part of your physical exam, you may also have:
A neurologic exam to identify possible nervous system problems. You may be asked to complete a few physical tasks, such as walking up and down a hall or getting up from a chair. By checking your reflexes and your ability to feel light touch, the exam can help determine whether you have a nerve problem. The doctor may also ask you to repeat a series of numbers or to answer simple questions about dates, places, and current events.
A mental health assessment. This test evaluates your emotional functioning and ability to think, reason, and remember. You will be asked questions to determine whether such conditions as depression, insomnia, or stress are contributing to or happening as a result of your chronic pain. These conditions often occur with chronic pain. You may also be asked about your use of alcohol and drugs. Answering these questions fully and honestly may help your doctor and you identify the sources of your chronic pain.
Diagnostic tests. These tests are often used to rule out other health conditions that can cause chronic pain. Tests may include:
Blood tests or other laboratory tests. A small sample of your blood is taken and then evaluated to see if you have an infection or other condition that could be causing your pain.
X-ratests take pictures of the inys or other imaging tests (such as CT scans, MRIs, or ultrasounds). These side structures of your body to look for disease and injury.
Electromyogram (EMG) and nerve conduction studies or other nerve tests. These tests measure muscle and nerve function to determine whether your chronic pain is related to muscle or nerve problems.
Angiogram or other vascular studies. This test injects a dye and inserts a small tube into your arteries to trace the movement of blood within your body.
Diagnostic nerve blocks. One example is an injection of a local anesthetic into or around a nerve to identify whether that nerve is causing the pain.