Chronic pain is a disease of the central nervous system. It is defined as “pain without apparent biological value that has persisted beyond normal tissue healing time”. This section looks at the types of pain and some of the causes of chronic pain.
Chronic pain is a disease of the central nervous system. It is defined as “pain without apparent biological value that has persisted beyond normal tissue healing time” It is also defined as pain that either persists beyond the point that healing would be expected to be complete (usually taken as 3-6 months) or that occurs in disease processes in which healing does not take place. The pain may be continuous or intermittent. Chronic pain can be experienced by those who do not have evidence of tissue damage or biological reason for pain (International Association for the Study of Pain, 2007). This ‘unknown cause’ factor often results in difficulty in reaching a diagnosis.
This type of pain can be nociceptive, or can be neuropathic i.e. handled by a dysfunctional nerve or cluster of nerve signals. People living with chronic pain often report hyperalgesia (increased sensitivity to pain), allodynia (heightened pain response to usually non-painful stimuli) or dysaesthesia (unpleasant abnormal sensations). Chronic pain can also arise from other types of pain.
Types of Pain
Pain can be classified by the type of pain or by body region. Classification by pain types includes:
Neuropathic pain: burning, stabbing, tingling, insect crawling, shooting, associated with allodynia, hypersensitivity or other sensory changes.
- Nociceptive pain: aching, boring, worse on movement, anatomically defined, fluctuates in severity.
- Mixed i.e. a combination of both neuropathic & nociceptive pain symptoms.
- Visceral pain: dull, diffuse, ill-defined.
- Autonomic symptoms: colour and temperature changes, sweating, trophic changes.
Although chronic pain is often neuropathic, it can also arise from other types of pain and it is possible to classify chronic pain by the underlying condition or body region which is causing the pain.
Neuropathic pain is caused by damage to or dysfunction of the nerves, spinal cord, or brain. Typical effects are felt as a burning, stabbing, stinging, numbing or tingling type of pain. This type of pain can often be spontaneous, and can be felt as sudden shocks. Neuropathic pain can also be felt as a hypersensitivity to touch or cold.
Neuropathic pain has several causes (Merck, 2009):
- Nerve compression: for example carpal tunnel syndrome
- Nerve damage: for example peripheral neuropathy resulting from diabetes mellitus or Guillain-Barré syndrome
- Abnormal or disrupted processing of pain signals by the brain and spinal cord: for example in ‘phantom’ pain following an amputation, post-herpetic neuralgia following shingles (herpes zoster) infection, and complex regional pain syndrome.
Nociceptive pain is the type of pain which results from injury or damage to body tissues e.g. a accident or trama, injury or burn, post-operative or due to a break or fracture. Nociceptive pain is usually well localised (dependent on area of tissue damage) and is typically described as a sharp or stabbing type of pain, or as an ache.
The most common type of nociceptive pain is lower back pain although it can also be a result from oncology therapies i.e. post surgery / post radiation treatments, malignant tumours, degenerative musculoskeletal diseases e.g. osteoarthritis and osteoporosis. (Merck, 2009).
Nociceptive pain can last long after the injury or damage which caused the pain. Psychological factors often play a part should nociceptive pain not resolve as quickly as expected (NHS Quality Improvement in Scotland, 2006).
Psychogenic pain is physical pain that arises from psychological factors, and by itself, occurs far less commonly than nociceptive or neuropathic pain. Although any pain type can be complicated by psychological factors such as mental, emotional or behavioural factors, it is controversial that chronic physical pain arises from purely psychological factors alone.
Psychological factors and symptoms of psychogenic pain often complicate pain related disabilities – although the pain has a physical cause, the psychological factors exacerbate or enhance the pain to be more severe than found in most individuals with a similar physical cause of pain.
The cycle where psychological factors exaggerate physical pain in this way is sometimes described as chronic pain syndrome. An individual with chronic pain anticipates its reoccurrence, becoming more anxious about the pain which in turn makes them less able to deal with the pain. The pain is then perceived to be more severe, which then precipitates more anxiety - becoming almost a self-fulfilling prophecy.
Chronic pain can be attributed many identifiable causes e.g. injury, arthritis, migraine, fibromyalgia, trigeminal, regional pain syndromes, infection etc
Causes of Chronic Pain
Headache and/or Migraine
- Cluster Headaches
- Drug or Substance overuse or misuse
- Giant cell (temporal) arteritis
- Temporo-mandibular joint dysfunction
- Trigeminal neuralgia
- Ankylosing spondylitis
- Carpel Tunnel Syndrom
- Chronic or repetitive overuse
- Mechanical low back pain
- Muscular strains
- Myofascial diseases
- Polymyalgia rheumatica
- Rheumatoid arthritis
- Brachial plexus traction injury/compression
- Complex regional pain syndrome
- Diabetic sensorimotor polyneuropathy
- Infections (e.g., HIV, Hepatitis C, post-herpetic neuralgia Herpes Zoster also know as Shingles)
- Multiple Sclerosis
- Pernicious anaemia (impaired absorption of Vit. B12)
- Spinal stenosis
- Thoracic outlet syndrome (blood vessel/nerve compression)
- Thyroid disease
- Polyneuropathies (damage affecting peripheral nerves)
- Polyradiculopathies (damage to serval nerve roots)
- Personality disorder
- Sleep disturbances.
Medical or Generalised Disease processes
Chronic Pain may arise from general medical or disease conditions. Regional pain includes:
- Abdominal (e.g. peptic ulcer, irritable bowel syndrome, pancreatitis, hernias, diverticular disease)
- Cardiovascular (e.g. ischaemic heart disease, coronary heart disease, angina, peripheral vascular disease, etc)
- Gynaecological (e.g. endometriosis)
- Obstetric (e.g. symphysis pubis dysfunction)
- Urological (e.g. interstitial cystitis)
Chronic Pain which results from disease processes includes:
- Endocrine – i.e. diabetes, joint pain etc.
- Infectious – i.e. hepatitis C, HIV Post-herpetic neuralgia
- Malignancy – cancer and post-treatment pain (e.g. chemotherapy, radiation or surgery)
- Rheumatological – i.e. fibromyalgia, rheumatoid arthritis, osteoarthritis etc
Referral to Healthcare Professional
If you think that you may have chronic pain, it is important that you seek the appropriate help and the first step is speaking to your GP.
It is important that you are prepared and able to give your GP as much information as possible during your visit. If you are anxious that you might forget something, write it down and bring it with you and you can also bring someone in with you. It will be helpful if you can inform your GP of the following:
- When pain began
- Was the onset of pain gradual, sudden, result of event/, trauma, accident
- Description of your pain (see section what is chronic pain LINK)
- Region(s) of your body that you are experiencing pain
- Does it radiate (e.g. starts and spreads to another location in your body)
- Describe how severe the pain can be on a daily, weekly basis, does it vary
- When you are most affected (is it worse in the morning / night)
- How often the pain occurs, is it constant, frequent, does it come and go
- How intense is your pain (how would you rate it 1 – 10 with ten being worst)
- If pain is affecting your ability to work, socialise or is it affecting your private / family life
- If pain is causing sleeplessness, poor concentration or low mood
Your GP may also ask you to use a Pain Diary which involves recording your level of pain (on a pain scale) several times a day over the period of a week. A useful online tool can be found at www.paintracker.ie
You will be asked to note activities or other things that seem to increase pain, and note when taking any medication the effect it has on your pain. This can be very helpful in establishing whether there is any particular pattern to the pain, or any triggers that could be avoided.
Your GP may also conduct a physical examination (which will vary depending on site and type of pain) to look for possible causes of pain and to rule out certain conditions. Once your GP has assessed your pain they may conduct further tests to try and determine the underlying cause of pain.
By describing your symptoms clearly and fully and the impact these have on your life your GP will be better positioned to make the correct diagnosis, begin treatment and / or refer you to specialist services.
Referral to a Pain Specialist
Chronic pain can be difficult to diagnose and treat and if your GP thinks that you may have chronic pain then he/she should refer you to see a pain specialist. If your GP is unwilling to do so, ask him / her to arrange for a second opinion. Please note that patients cannot make an appointment for themselves, the referral must come via a GP or other medical professional.
Be prepared for your appointment and again if you are anxious that you might forget something write it down or bring someone along with you. Keep a pain diary (either on paper or by using an app e.g. paintracker.ie). A Pain Diary involves recording your level of pain several times a day over a period of time. You note activities or other things that seem to increase pain, and note when taking any medication the effect it has on your pain. This can be very helpful in establishing whether there is any particular pattern to the pain, or any triggers that could be avoided.
Pain Management Programme
A Pain Management Program (PMP) is a psychologically-based rehabilitative treatment for people with persistent pain. It is delivered in a group setting by an interdisciplinary team of experienced health care professionals working closely with patients. Some Pain Centres may run Pain Management Programs that aim to teach a group of patients with similar problems about pain, how best to cope with it and how to live a more active life.
For the majority of people, attending a Pain Management Program reduces the disability and distress caused by persistent pain by teaching physical, psychological and practical techniques to improve quality of life. It differs from other treatments provided in Pain Clinics in that pain relief is not the primary goal, although improvements in pain following participation in a Pain Management Program have been demonstrated.
Referral to a Pain Management Programme is usually through your general practitioner to your local pain clinic.
There are public pain management programmes in:
- St Vincent’s University Hospital, Dublin
- Tallaght University Hospital, Dublin
- Mater Misericordiae University Hospital
- Mercy University Hospital, Cork
In addition, St James Hospital, Dublin offer mindfulness meditation while in Galway, the Galway University Hospital is also developing an online program to allow access by patients in all regions of the country.
A video link is attached here which demonstrates what you can expect from a pain management programme.
Self-Management fits well with clinical approaches and the sooner you start the better. It's not easy but it is possible. A lot of people make huge improvements in the quality of their life when they thought all was lost. While there is no immediate cure for Chronic Pain implementing strategies/techniques through self-management can help reduce your pain, improve the quality of your life and puts you, not the pain, in control.
Self Management is an approach to improving health and well-being by addressing the impact chronic pain has on life i.e. stress, anxiety, poor sleep and over-doing things. It is important to take control wherever possible through improving understanding and building skills in relaxation, stress management, pacing and challenging negative thinking. Details of our self-management meetings can be found here