Chronic Pain Disorder

What chronic pain is

Acute pain is a warning signal after injury or illness and fades as tissues heal. Chronic pain persists beyond normal healing time, usually defined as more than 3 months. The World Health Organization's ICD-11 classification divides it into:

Why pain becomes chronic

Pain is produced by the brain in response to signals from the body. When pain persists, the nervous system can change:

• Central sensitization: nerves in the spinal cord and brain become more responsive, so normal touch or movement hurts (allodynia) and painful stimuli hurt more (hyperalgesia).
• Reduced pain-blocking signals from the brain.
• The stress system stays activated, worsening sleep, mood and muscle tension.

These changes are real and measurable. They explain why pain can persist after an injury has healed and why treatment targets the nervous system as well as the body.

Risk factors

• Previous injury, surgery or painful illness
• Female sex and older age
• Depression, anxiety and PTSD
• Poor sleep
• Adverse childhood experiences and ongoing stress
• Obesity and physical inactivity
• Smoking
• Physically demanding or unsatisfying work
• Fear of movement and catastrophizing (expecting the worst)

Symptoms and effects

• Pain that may be aching, burning, shooting, stabbing or throbbing, constant or fluctuating
• Stiffness and reduced movement
• Fatigue
• Poor sleep: pain disturbs sleep, and poor sleep amplifies pain
• Depression and anxiety, affecting up to half of people with chronic pain
• Difficulty concentrating
• Withdrawal from work, social life and hobbies
• Financial and relationship strain

Assessment

A primary care doctor or pain specialist will:

1. Take a detailed history: where the pain is, its pattern, triggers, past treatments and their effects.
2. Ask about sleep, mood, work, daily activity, and what matters most to you.
3. Examine you and, where appropriate, order tests to look for treatable causes. Many people with chronic primary pain have normal scans, which does not mean the pain is not real.
4. Screen for depression, anxiety and substance use.
5. Agree on goals focused on function, such as walking further or returning to work, as well as pain reduction.

Treatment

The best results come from combining approaches.

Physical activity

Regular exercise is one of the most effective treatments for most chronic pain. Start low and build up gradually ("pacing"). Walking, swimming, cycling, strength training, yoga and tai chi all help. Some increase in pain at first is common and not harmful.

Psychological therapies

• Cognitive behavioral therapy (CBT): reduces the impact of pain by changing unhelpful thoughts and behaviors.
• Acceptance and commitment therapy (ACT): recommended by NICE for chronic primary pain, helping people live well alongside pain.
• Pain reprocessing therapy and mindfulness-based approaches help some people.

Sleep

Treating insomnia with CBT for insomnia (CBT-I) improves pain and mood. See insomnia.

Pain management programs

Multidisciplinary programs combine physical therapy, psychology, education and occupational therapy, and help people return to activities and work.

Medicines

• For chronic primary pain, NICE recommends considering certain antidepressants (such as duloxetine or amitriptyline) and advises against starting most other medicines, including opioids, gabapentinoids and NSAIDs, because of limited benefit and potential harm.
• For secondary pain, treatment depends on the cause: NSAIDs for osteoarthritis flares, nerve pain medicines for neuropathy, disease-modifying drugs for inflammatory arthritis.
• Topical treatments such as NSAID gels, lidocaine or capsaicin for localized pain.
• Opioids: CDC guidance advises that non-opioid treatments are preferred for chronic pain. When opioids are used, the lowest effective dose is prescribed with regular review, and naloxone should be available.

Other approaches

• Acupuncture for some types of chronic primary pain
• Transcutaneous electrical nerve stimulation (TENS)
• Interventional procedures such as nerve blocks or spinal cord stimulation for selected conditions
• Weight loss and stopping smoking

Living with chronic pain

• Pace activities: break tasks into smaller parts with rests, rather than doing too much on good days.
• Keep a regular sleep schedule.
• Stay connected with friends, family and work where possible.
• Plan for flare-ups with a written plan of what helps.
• Track progress in what you can do, not just pain scores.

Outlook

Chronic pain often fluctuates and can improve substantially with the right combination of treatments. Many people regain function and quality of life even if some pain persists. Early, active management reduces the chance of long-term disability.

Frequently asked questions

What is chronic pain disorder?

Chronic pain disorder is pain that lasts or keeps returning for more than 3 months and causes significant distress or disability. It can be caused by an ongoing condition or exist as a condition in its own right, as in fibromyalgia or chronic low back pain.

Why does chronic pain continue after an injury heals?

The nervous system can become sensitized, so it continues to produce pain signals even after tissues have healed. Stress, poor sleep, low mood and inactivity can reinforce this. These changes are real and can be improved with treatment.

What is the best treatment for chronic pain?

There is no single best treatment. The most effective approach combines gradual physical activity, psychological therapies such as CBT or ACT, good sleep, and selected medicines. Multidisciplinary pain programs help people with complex pain.

Are opioids good for chronic pain?

For most chronic pain, opioids are not recommended as first-line or long-term treatment. Their benefit tends to fade over time, while risks such as dependence, overdose and worsened pain sensitivity increase. Non-opioid treatments are generally preferred.

Can chronic pain cause depression?

Yes. Chronic pain and depression often occur together and worsen each other. Up to half of people with chronic pain experience depression or anxiety. Treating both together improves pain, mood and function.