Nociceptive and neuropathic pain: What are they?
Nociceptive pain is the most common type of pain people experience. It develops when the nociceptive nerve fibers are triggered by inflammation, chemicals, or physical events, such as stubbing a toe on a piece of furniture.
This article focusses on the difference between nociceptive pain and neuropathic pain, as well as their causes and treatments.
What is nociceptive pain?
Nociceptive pain may develop following a specific situation such as a sports injury, stubbed toe, or arthritis.
Nociceptive pain is usually acute and develops in response to a specific situation. It tends to go away as the affected body part heals. For example, nociceptive pain due to a broken ankle gets better as the ankle heals.
The body contains specialized nerve cells called nociceptors that detect noxious stimuli or things that could damage the body, such as extreme heat or cold, pressure, pinching, and chemicals. These warning signals are then passed along the nervous system to the brain, resulting in nociceptive pain.
This happens very quickly in real time, which is why people know to remove their hands if they touch a hot oven or take the weight off an injured ankle.
Nociceptors can also be found in the internal organs, although their alarm signals are less easy to pinpoint and may not always be consciously felt.
The information provided by nociceptive pain can help the body protect and heal itself.
What is neuropathic pain?
Neuropathic pain is a medical term used to describe the pain that develops when the nervous system is damaged or not working properly due to disease or injury.
It is different from nociceptive pain because it does not develop in response to any specific circumstance or outside stimulus.
In fact, individuals can suffer from neuropathic pain even when the aching or injured body part is not actually there. This condition is called phantom limb pain, which may occur in people after they have had an amputation.
Neuropathic pain is also referred to as nerve pain and is usually chronic.
Many different conditions and diseases cause neuropathic pain, including:
CLBP is a common complaint, but often the pain is neuropathic rather than nociceptive.
To access proper treatment, it is very vital to determine whether an individual is suffering from neuropathic or nociceptive pain.
Chronic low back pain (CLBP) is a very common complaint, but in 90 percent of cases, doctors are not able to identify a physical cause. Often, some of the discomfort people have from CLBP is neuropathic pain.
A diagnostic test called the "painDETECT questionnaire" was developed to help doctors identify the presence of both neuropathic and nociceptive pain in people with CLBP.
This test is now widely used to evaluate neuropathic pain in many different conditions and diseases, including rheumatoid arthritis.
When doing the questionnaire, a person will be asked to answer 9 questions. Seven of the questions ask them to rate different sensations from their pain on a scale from 0 to 5. They will also be asked how long the pain lasts, rated from -1 to +1, and whether or not the pain radiates, rated from 0 to 2.
The higher the score, the higher the level of neuropathic pain an individual is likely to be experiencing.
People with diabetes are advised to watch for symptoms of neuropathic pain, particularly in the feet. Neuropathy in the lower limbs is very common in people with diabetes and is a leading cause of amputation.
Neuropathic pain in people with diabetes often begins with numbness, weakness, or burning in the toes. This pain can also get worse at night and make it difficult to sleep.
Location of pain
The most common areas for people to experience nociceptive pain are in the musculoskeletal system, which includes the joints, muscles, skin, tendons, and bone.
Internal organs, such as the intestines, lungs, and heart, can also be subject to nociceptive pain, along with the smooth muscles.
In 2005, it was estimated that there were 1.6 million people who had lost a limb in the United States. Researchers believe that vascular problems, trauma, cancer, and armed conflicts will lead to that number rising to 3.6 million by 2050.
It is estimated that 42.2–78.8 percent of individuals who have had a limb amputated will suffer from phantom limb pain. This kind of neuropathic pain can develop anywhere a limb has been removed.
Roughly half of all people with diabetes experience diabetic peripheral neuropathy (DPN), which is nerve pain affecting the feet and hands. The toes are usually the first part of the body to be affected.
People with diabetes can also develop neuropathy in other parts of the body, including the front of the thighs, near the eyes, and the wrists.
Many people with cancer experience neuropathic pain in the back, legs, chest, and shoulders due to tumors affecting the spinal cord. They may also experience neuropathic pain due to medication or surgery.
The lower back is one area where individuals can experience both neuropathic and nociceptive pain.
Codeine may be used as a treatment for nociceptive pain.
It is important to keep in mind that an individual can experience neuropathic and nociceptive pain at the same time. Paying attention to key differences can improve the quality of life for people dealing with pain and help them get the correct treatment.
As nociceptive pain can develop anywhere on the body in response to heat or trauma, it can have many different characteristics. It is usually most severe at the time of injury, but may also be worse first thing in the morning or during activity,
Treatment for nociceptive pain varies depending on the cause. Unlike neuropathic pain, nociceptive pain frequently responds well to treatment with opiates, such as codeine.
People with neuropathic pain report a variety of symptoms, including:
- sharp, shooting, searing, or stabbing pain
- tingling sensations
- extreme sensitivity to touch
- insensitivity to heat or cold
- muscle weakness
- worse pain at night
As with nociceptive pain, one of the first and most critical steps in treating neuropathic pain is treating the underlying condition.
Individuals with DPN should work with their doctor to find medications that help control their diabetes and prevent further DPN. Their doctor may also prescribe treatment to reduce the pain and injuries associated with this condition.
People with neuropathic pain due to cancer may find relief with anticonvulsants, local anesthetics, and antidepressants. Treatment will vary between individuals and the specific cause of their pain.
Studies suggest that one of the best treatments for neuropathic pain due to phantom limb pain is prevention. If a person receives extensive pain treatment before their amputation surgery, they seem less likely to develop phantom limb pain afterward.