Like any chronic condition, chronic pain is something that has been around for some time. This means that it is not a passing problem, such as a one-off headache. Nor is it something that comes and goes - like migraines, for example – although its level of intensity may alter as time passes. Generally speaking, doctors consider constant pain that has not gone away for something like three to six months to be chronic. That said, some specialists believe that pain must have been endured for around a year to be truly chronic. There are many causes of chronic pain. In some cases, it may come about directly from another condition which is, itself, causing pain. In other cases, it may be that the brain is malfunctioning in some way to make people feel pain when there appears to be no cause. A typical form of chronic pain comes from spinal problems, usually because the nervous system in the spinal cord is sending pain signals to the brain. People with heart disease and certain respiratory conditions are more likely to suffer from this type of pain than the general population.