The roots of CPS are both physical and mental. Some experts think that people with the condition have a problem with the system of nerves and glands that the body uses to handle stress. That makes them feel pain differently.
Other experts say CPS is a learned response. When you're in pain, you can start to repeat certain behaviors. For example, you might complain about your pain, lie down to rest, use pain relievers, or take time off from work. These behaviors can act like little rewards that encourage the pain to continue, even after the original cause of the pain is gone.
CPS can affect people of all ages and both sexes, but it's most common in women. People with major depression and other mental health conditions are more likely to get CPS.