How Pain Works

Pain Management

Physicians treat pain in numerous ways. Pain management can include medications, surgery, alternative procedures (like hypnosis, acupuncture, massage therapy and biofeedback) or combinations of these approaches.

Different types of pain medications act at different places in the pain pathways. The type of medication depends upon the source of the pain, the level of discomfort and possible side effects.

Non-opioid analgesics, like aspirin, acetaminophen (Tylenol), ibuprofen (Advil), and naproxen (Aleve), act at the site of pain. The damaged tissue releases enzymes that stimulate local pain receptors. Non-opioid analgesics interfere with the enzymes and reduce inflammation and pain. They can have some adverse effects in the liver and kidneys and can cause gastrointestinal discomfort and bleeding with prolonged use.
Opioid analgesics act on synaptic transmission in various parts of the central nervous system by binding to natural opioid receptors. They inhibit ascending pathways of pain perception and activate descending pathways. Opioid analgesics are used for higher levels of pain relief -- they include morphine, meripidine (Demerol), propoxyphene (Darvon), fentanyl, oxycodone (OxyContin) and codeine. They can be easily overdosed and become addictive.
Adjuvant analgesics (co-analgesics) are primarily used for treating some other condition, but they also relieve pain. These compounds are useful in treating neuropathic pain (chronic pain that comes from injury to the central nervous system). They include the following:
Anti-epileptic drugs reduce membrane excitability and action potential conduction in neurons of the central nervous system. Tricyclic antidepressants affect synaptic transmission of serotonin and norepinephrine neurons in the central nervous system, thereby affecting pain-modulating pathways. Anesthetics block action potential transmission by interfering with sodium and potassium channels in nerve cell membranes. Examples include lidocaine, novocaine and benzocaine.

Surgery

In extreme cases, surgeons may have to sever pain pathways by altering areas of the brain associated with pain perception -- or performing a rhizotomy (which destroys portions of peripheral nerves) or a chordotomy (destroys ascending tracts in the spinal cord). These surgeries are usually a last resort.

Surgical interventions can be aimed at eradicating the source of the pain. For example, many people suffer back pain from herniated disks between the vertebrae. An inflamed disc can compress a nerve and cause neuropathic pain. If the patient does not respond to medication, a surgeon might try to remove at least part of the disc and relieve pressure on the nerve.

Alternative Therapy

These approaches do not involve drugs or surgery.

Chiropracty manipulates joints to relieve compression of nerves.
Massage stimulates blood flow, relieves muscle spasms and increases somatosensory information, which can relieve pain through the gate control theory (see previous page).
Hot applications increase blood flow, and cold applications reduce inflammation, which contributes to pain.
Stimulation of the skin with small electrodes can close the gate to pain.
Acupuncture may stimulate nerve cells and release endorphins. The increased stimulation might also close the gate to pain.
Mental control techniques rely on the ability of the mind and emotions to control and alleviate pain through descending neural pathways. They include relaxation techniques, hypnosis, biofeedback and distraction techniques.

Pain-management plans involve the participation of doctors, patients, family members and other caregivers. As with any medical treatment, the source ofpain, pain tolerance, and the potential benefits and risks of treatmen must be considered.

To learn more about pain, take a look at the links below.

Sources

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