Referred pain is a phenomenon in which a pathology in one area of the body causes pain in another location. The classic example of referred pain is the pain in the left arm and neck associated with a heart attack or angina episode. In this case, the pain is actually occurring in the heart, but the patient experiences the pain in another location. While this type of pain has been documented and studied extensively, researchers are not entirely sure about what causes it.
When referred pain occurs, it can be somewhat frustrating for both patient and doctor. The patient comes to the doctor to treat shoulder pain, for example, and the doctor cannot find anything wrong with the shoulder which would cause pain. The doctor may say that nothing can be done, which is upsetting for the patient, because he or she is experiencing real pain despite the lack of any obvious cause.
Some types of referred pain, such as the arm and neck pain from heart attacks, are well known, and if a patient comes to a doctor with this sort of pain, the doctor may order tests on the heart. In other cases, a doctor may not immediately connect a report of pain with specific cases of pain, in which case treatment may be delayed. At times, this can be very problematic for the patient, because medical conditions tend to grow worse when no treatment is offered.
The phantom limb pain experienced by amputees is another example of referred pain. This type of pain is well known and thoroughly documented, but unfortunately it is also very difficult to treat, because the brain is relaying signals from nerves which do not exist.
Classically, referred pain involves a problem with the visceral organs which causes pain in an extremity. Some researchers have theorized that this may have something to do with the fact that nerves from the viscera typically carry very low sensory input, and nerves from the extremities are more finely tuned. When these nerves happen to meet up in the same place, the brain may get confused and think that the input from the viscera is coming from an extremity.
The treatment for this condition is to determine the underlying cause and address it. Patients who experience persistent widespread pain with no obvious cause may want to suggest that they are experiencing referred pain, and ask a doctor for additional medical tests which can be used to determine the presence of a problem elsewhere in the body.
