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Chronic Pain


James C. Watson

, MD, Mayo Clinic College of Medicine and Science

Reviewed/Revised Jun 2022 | Modified Aug 2023

Chronic pain is pain that lasts or recurs for months or years.

Usually, pain is considered chronic if it does one of the following:

  • Lasts for more than 3 months

  • Lasts for more than 1 month after the injury or problem that originally caused pain has resolved

  • Recurs off and on for months or years

  • Is associated with a chronic disorder (such as cancer, arthritis, diabetes, or fibromyalgia) or an injury that does not heal

Chronic pain sometimes occurs when nerves become more sensitive to pain. For example, the original cause of the pain may repeatedly stimulates the nerve fibers and cells that detect, send, and receive pain signals. Repeated stimulation can change the structure of nerve fibers and cells (called remodeling) or make them more active. As a result, pain may result from stimulation that might not ordinarily be painful, or painful stimuli may seem more severe. This effect is called sensitization.

Also, areas of muscle or connective tissue may become very sensitive and tender to the touch. These areas are called trigger points because touching these areas frequently triggers unexplained pain that radiates to other areas of the body.

Did You Know...

  • Chronic pain sometimes occurs when the original cause of the pain stimulates nerves repeatedly and such stimulation can physically change the nervous system in ways that make the pain worse and last longer.

Anxiety, depression, and other psychologic factors may help explain why some people experience pain as more unpleasant than others do and why pain limits their activities more. For example, people with chronic pain know it will recur and may become fearful and anxious as they anticipate the pain. Fear and anxiety can reduce the production of substances that reduce the sensitivity of nerve cells to pain. These changes in sensitivity to pain partly account for pain that persists after its cause resolves and for pain that feels more severe than expected.

Sometimes what originally caused the pain is obvious—for example, when people have had an injury that resulted in chronic back pain. Or the cause may be unknown—for example, when people have a chronic headache.

Symptoms of Chronic Pain

Chronic pain may occur in different parts of the body in different people (for example, it may occur in the back in one person and in the fingertips in another). Also, the sensation of pain may be different. For example, the pain may feel like throbbing, stabbing, burning, or stinging. It may be constant or may come and go, and the intensity of the pain may vary.

People with chronic pain often also feel tired, have problems sleeping, lose their appetite and/or taste for food, and lose weight. Their sex drive may decrease. These problems develop gradually. Constant pain can prevent people from doing what they usually enjoy. They may become depressed and anxious. They may stop their activities, withdraw socially, and become preoccupied with physical health.

Diagnosis of Chronic Pain

  • A doctor's evaluation

  • Sometimes a mental health evaluation

Doctors thoroughly evaluate the person to identify the cause of pain and its effect on daily life. If no cause is identified, doctors then focus on relieving pain and helping the person function better.

Treatment of Chronic Pain

  • Drugs to relieve pain

  • Physical methods (such as physical therapy)

  • Psychologic and behavioral therapy

If a cause of chronic pain is identified, it is treated.

Treatment of chronic pain may include the following:

If treatments are ineffective, doctors may refer people to a pain clinic.


In most people taking pain relievers (analgesics) for chronic pain, the pain's intensity varies throughout the day. Intensity varies based on several factors, such as the following:

  • Characteristics of the affected nerves (for example, how quickly they send signals and where the nerves are located)

  • Activities that can cause pain (such as moving or touching the affected area)

  • Stress

  • Dose or schedule of pain relievers

Depending on the severity of the pain, the following types of drugs may be used to treat chronic pain:

Sometimes a combination of drugs may relieve pain more effectively than a single drug.

Chronic pain is usually treated first with acetaminophen or with nonsteroidal anti-inflammatory drugs (NSAIDs) Nonsteroidal Anti-Inflammatory Drugs Pain relievers (analgesics) are the main drugs used to treat pain. Doctors choose a pain reliever based on the type and duration of pain and on the drug's likely benefits and risks. Most pain... read more , such as ibuprofen or naproxen. NSAIDs not only relieve pain, but they may also reduce the inflammation that often accompanies and worsens pain. However, if taken in high doses or for a long time, NSAIDs can have serious side effects, including irritation of the stomach's lining, an increased tendency to bleed, kidney problems, and an increased risk of heart and blood vessel (cardiovascular) disorders.

Adjuvant analgesics are commonly used to treat chronic pain. These drugs are thought to work by changing the way nerves process pain (rather than directly stopping the sensation of pain).

The adjuvant analgesics most commonly used for pain are

Before prescribing opioids for any type of chronic pain, doctors consider the following:

  • What the usual treatment approach is

  • Whether there are other treatments that could be used

  • Whether the person has a high risk of side effects from an opioid

  • Whether the person is at risk of misuse or abuse of an opioid drug or is likely to use the drugs for other purposes (for example, to sell them)

Doctors may refer people to a pain specialist or a mental health care practitioner who has expertise in substance misuse if the risk of having a problem is high. For example, people who have had an addiction usually need a referral.

When opioids are prescribed for chronic pain, doctors explain the nature of the person's disorder (if known) and the risks and benefits of other possible treatments, including nonopioid drugs and no treatment. Doctors ask the person about their goals and expectations. They usually give the person written information that describes the risks of taking opioids. After the person discusses this information with the doctor and understand it, the person is asked to sign an informed consent Informed Consent People have the right to information about potential harms, benefits, and alternative treatments when making decisions about medical care, and they have the freedom to accept or refuse care... read more document.

When doctors prescribe an opioid for chronic pain, they explain the risks and side effects of opioids. People are advised

  • Not to drink alcohol or take antianxiety drugs or sleep aids when taking the opioid

  • To take the recommended dose at the recommended times and not to change the dose

  • To store the opioid in a safe, secure place

  • Not to share the opioid with anyone

  • To contact their doctor if the drug makes them drowsy or they have any other side effects (such as confusion, constipation, or nausea)

  • To dispose of unused pills as directed

  • To keep naloxone (an opioid antidote) on hand and to learn and teach family members how to administer it if an opioid overdose occurs

If an opioid is prescribed, doctors have usual practices to ensure the person's safety. Doctors typically ask the persons to get opioid prescriptions only from one doctor and fill prescriptions at the same pharmacy every time. They see the person for follow-up visits frequently and monitor the use of the drug to make sure it is safe and effective. For example, doctors may periodically test the person's urine to determine whether the drug is being taken correctly. They also ask the person to sign an agreement that specifies conditions required for opioid use, including any monitoring that may be needed.

For people with pain due to cancer or another terminal disorder, concerns about side effects should not limit the use of opioids because side effects can usually be prevented or managed, and addiction is less of a concern.

Physical or occupational therapy

Physical or occupational therapists use various techniques to try to relieve chronic pain and help people function better. If trigger points are present, practitioners may use a spray to cool the area, then stretch the muscle. This method (called stretch and spray) can help lessen pain. Wearing an orthosis (a device that supports damaged joints, ligaments, tendons, muscles, and bones) helps some people.

Sometimes doing exercises or increasing activity level helps. For example, walking regularly can help relieve lower back pain more effectively than resting in bed.

Complementary and integrative medicine

Counseling and behavioral techniques

Counseling or psychotherapy can help people function better, even if it does not reduce pain. Doctors may recommend specific ways to gradually increase physical and social activities. People are advised not to let pain derail their commitment to better functioning. When this approach is used, many people report a decrease in pain. Doctors applaud progress, encourage people to continue improving, and continue to treat the pain as needed.

Doctors may also talk with family members or fellow workers to discourage them from doing anything that keeps the person focused on the pain. For example, they should not constantly ask about the person's health or insist that the person do no chores.

Nerve block

A nerve block is frequently used to treat pain caused by damage to a specific large nerve. For this procedure, a nerve pathway that transmits pain signals is disrupted by one of the following:

  • Injecting the area around the nerves with a local anesthetic to prevent the nerves from sending pain signals (doctors commonly use ultrasonography to help them locate the nerves to be treated)

  • Injecting the area around nearby collections of nerve cells called ganglia to help regulate the transmission of pain signals

  • Injecting a caustic substance (such as phenol) into a nerve to destroy it

  • Freezing the nerve (cryotherapy)

  • Burning the nerve with a radiofrequency probe

Nerve blocks are often used to treat low back pain caused by pressure on (compression of) spinal nerves (which connect the spinal cord with other parts of the body). Nerve blocks may also be used to treat severe cancer pain near the end of life and severe, persistent neuropathic pain when drugs cannot relieve the pain.

Pain rehabilitation programs

Doctors may recommend a pain rehabilitation program for people with chronic pain. These programs are managed by an interdisciplinary team that includes psychologists, physical therapists, doctors, nurses, and sometimes occupational therapists and integrative medicine practitioners. The programs include education. cognitive behavioral therapy, physical therapy, simplification of the drug regimen, and sometimes gradually decreased use of a pain reliever. They focus on the following:

  • Restoring function

  • Improving quality of life

  • Helping people control their own life, despite their chronic pain

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