Chronic pain testing relies on the medical history and physical exam, and may also include a pain diary, blood tests, nerve studies, or imaging studies.
If you have chronic pain, your doctor will want to learn everything possible about your pain and its possible causes, in order to provide you with the best treatment. This includes searching for an underlying cause (which may be treatable), as well as treating the pain itself.
There is no objective test that can measure the exact amount of pain and pinpoint its location, because pain is a multifaceted personal experience. This means that your doctor’s investigation of your pain will rely heavily on your description of your pain.
Some of the tests that may be used to diagnose chronic pain include:
• Medical history and physical exam
• A pain diary
• Blood tests
• Nerve studies
• Imaging studies
Your medical history will guide your doctor’s choice of other tests to diagnose your pain. This includes any previous illnesses, injuries, or surgeries that you may have had, your current health including any medical conditions, as well as information about your pain. Your doctor will ask what kind of pain you have (for example, sharp or dull; throbbing or aching), whether it’s associated with any other symptoms, what makes it better or worse, and many other factors.
A physical examination will also help your doctor determine a possible cause for your pain. Your doctor will do a neurological examination, which checks the functioning of your nervous system. This may include performing various tasks like moving parts of your body, walking down the hallway, and detecting light touch on different parts of your body.
Because it can be difficult to generalize about your pain, your doctor may ask you to keep a pain diary. In this document, you will keep daily logs of when you have pain and how bad it is, along with other factors in the environment (such as what activities you were doing). This could help your doctor find a cause for your pain, and may assist in treating the pain effectively.
Your doctor may determine that blood tests would be helpful in diagnosing the cause of your chronic pain. Blood tests may be able to find signs of an infection or inflammation that can cause pain and may be treatable.
Nerve studies look at the functioning of specific nerves in your body to determine whether nerve damage is causing your pain. For example, nerve conduction studies run a small electrical current through the nerve to determine how quickly the nerve conducts the signal; damaged nerves conduct slower or not at all. Sometimes, a diagnostic nerve block is used, in which a numbing medication is injected near a certain nerve to see if that treats the pain.
Other tests can sometimes be useful in finding the cause of chronic pain. Imaging studies like X-rays, CT scans, and MRI scans can visualize various structures inside your body that may be damaged, causing your pain. An angiogram studies the arteries in your body by injecting a dye into them and then using an X-ray to trace the dye’s movement through your blood vessels. In some cases of chronic pain, this can be a useful test.
National Institutes of Health. “Chronic Pain: Symptoms, Diagnosis, & Treatment.” NIH Medline Plus 6, no. 1 (Spring 2011): 5-6. http://www.nlm.nih.gov/medlineplus/magazine/issues/spring11/articles/spring11pg5-6.html
National Cancer Institute. “Pain.” (2015) http://www.cancer.gov/about-cancer/treatment/side-effects/pain
American Academy of Pain Medicine. “AAPM Facts and Figures on Pain.” http://www.painmed.org/patientcenter/facts_on_pain.aspx