Chronic pain is defined as pain that persists for more than three months, in contrast to acute pain which is limited. Chronic pain may be the result of injury, infection, or chronic disease and can manifest as low back pain, migraines, arthritis, neuralgias or neurological diseases affecting various nerves, cancer, and even psychogenic pain where no physical cause can be found. Chronic pain more commonly affects older adults and can be unrelenting (without relief) or intermittent (continuing to come and go).

Symptoms of chronic pain last more than three months and are generally associated with its origin, such as low back pain due to injury or disease; arthritis pain associated with joints and bones; headaches, such as recurring migraines; neurogenic pain from nerve or central nervous system diseases and disorders; psychogenic (no known disease or injury) pain; and may be combined with co-morbid (more than one) conditions, such as chronic fatigue syndrome; fibromyalgia (muscle pain); inflammatory bowel disease; interstitial cystitis (bladder infection); temporomandibular joint (TMJ) dysfunction; and vulvodynia (vulvar pain). Chronic pain symptoms may be aggravated by environmental and psychological factors. Some patients with chronic pain may also experience mood disorders, such depression and anxiety.

Chronic pain is considered to be a major medical disorder that requires treatment and may be incurable. Treatments for chronic pain depend on its type, causes, and condition, and often involve seeing different specialists that are part of a pain management and rehabilitation team. Common treatments for chronic pain may include acupuncture; anesthetic pain blocks; epidural steroid injections; antidepressants; application of heat and cold; biofeedback; behavior modification therapy; brain stimulation; exercise; local electrical stimulation; hypnosis; over-the-counter medications, such as aspirin or acetaminophen; non-steroidal anti-inflammatory drugs (NSAIDs); placebos; prescription pain medicines, such as opioids; physical and occupational therapy, such as massage and whirlpool treatments; meditation; psychotherapy and group therapy; relaxation techniques; stress management; or surgery. Most often, treatment for chronic pain focuses on decreasing pain symptoms, while managing pain long-term.