What is chronic pain?
Chronic pain often results from changes in the sensitivity of your nerves, spinal cord and brain. In some people, the nervous system becomes “hypersensitive” to a pain message after an injury. As a result, the brain continues to interpret the firing of the nerves as a feeling of pain, when in fact the injury has already healed and there is no danger. In effect, it is receiving a false alarm.
Chronic pain can affect many aspects of your life. For instance, it can bring down your mood and interfere with your sleep and other activities such as attending school or work, participating in sports, doing hobbies and seeing friends. We don’t exactly understand why some people experience chronic pain and can’t predict who will develop it after an injury.
Understanding some key terms related to chronic pain
There are a number of ways to classify pain. This can sometimes be confusing! The tables over the following pages describe the various types of chronic pain in more detail. These tables provide an overview of the most common types of pain. However, there are many other, less common types of pain that may not be discussed here. Talk to your healthcare provider if you have any questions about the type of pain that affects you.
Here are some of the different ways to classify, or categorize, pain:
1. Duration
Pain can be defined in terms of its duration. Acute pain is brief, but chronic pain lasts a long time.
2. Location
Pain can also be defined by its location in the body or its link with an underlying disease, such as arthritic pain.
3. Frequency
Chronic pain can be described as persistent or recurrent.
Persistent chronic pain is pain that lasts for longer than the normal time needed for healing, usually between six weeks and three months.
Recurrent pain is pain that occurs at least three times within three months.
4. Mechanism
Pain can also be defined by the underlying mechanism or what causes it. Two main mechanisms cause pain.
Nociceptive pain occurs when pain messages are sent to your nerves and brain by receptors in your tissues (such as an organ or your hands or feet).
Neuropathic pain occurs when pain messages are generated by nerves in your body or the receiving centre in the brain.
Many people with chronic pain have a combination of both nociceptive and neuropathic pain - this is called mixed pain.