Chronic Pain is a complex phenomenon that over the years has proven to be quite difficult to define by health care professionals, as well as being equally challenging to describe by those who suffer with it. Repeated attempts have been made over the past 25+ years by academia to give chronic pain a concise but complete definition, but even pain specialists who have worked in the field for as many years continue to fall short.

The "official" definition of pain, according to the American Pain Society (APS) is "An unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage." The APS goes on to state that pain without tissue damage occurs because of psychological reasons, and that there is no way to distinguish their experience from that due to tissue damage, so if they report it as pain, it should be taken as such. As long as I've been working in the field of chronic pain, I have hoped that a better definition of pain would take the place of this one, but so far one has not.

The difficulty in adequately describing chronic pain stems from several factors: 1) The experience of pain is a highly subjective one, which is experienced differently depending on the individual, 2) No diagnostic study exists which measures or quantifies pain, moreover, one which will even tell us definitively whether or not pain is actually present, and 3) the vast spectrum of diagnoses that can cause chronic pain, and the even more profoundly diverse number of ways chronic pain may be manifest.

Patients perceptions of, and reactions to chronic pain, are almost as varied as the number who suffer from it. And what remains more of an enigma, even after so many years of academic and clinical study, is the fact that pain specialists are unable to predict the degree of disability and severity of pain based on an individual's pain diagnosis, medical history, comorbid conditions and demographics, as with most other health conditions.

For example, one patient may have a ruptured intervertebral disc that shows up as an incidental finding on an imaging study which does not cause the patient any pain whatesoever. Another person with the same medical history, demographics and comorbid conditions may have only a very mild disc bulge, yet their pain is excrutiating, unrelenting and even causes pain in their buttocks and legs .

Chronic Pain of the low back is one of the top reasons for medical office visits in the United States and one of the number one causes of disability. Low back pain can be caused by many different reasons, some of which are Lumbar Degenerative Disc Disease, Lumbar Disc problems which may include bulging, protruding, or herniated disc (Disc Displacement), Post Lumbar Laminectomy Syndrome, Lumbar Stenosis, Lumbar Radiculopathy and Chronic Lumbar Strain.

Numerous surgeries are performed each year for lower back problems, and studies show that many times pain continues after patients have corrective surgery of the lumbar spine. The lumbar spine is often injured when a person is involved in heavy lifting, repetitive bending and falls. Currently, there is not one definitive treatment of low back issues that is guaranteed to solve the problem. Often times a person who undergoes surgery for lumbar spinal issues will continue to experience the same, or worse level of pain after surgery as prior to undergoing surgery.

Chronic Pain of the Neck, like Low Back Pain, is often caused by spinal issues. Common causes of neck pain include Cervical Degenerative Disc Disease, Cervical Stenosis, Post Cervical Laminectomy Syndrome, Cervical Disc Displacement, Cervical Radiculopathy and Cervicalgia. Chronic Neck Pain can also result in severe headaches as well as pain which radiates down the arm, hand and fingers and numbness and tingling in these same areas. Surgical intervention of the neck, as with surgery of the lower back, is unpredictable--sometimes it is helpful, but many other times it results in the same, or worse pain than before. Chronic Neck Pain is a common cause of missed work and disability in the United States.

Chronic Pain of the thoracic area, the middle portion of the spine, is also many times related to spinal problems. However, the most frequent cause of pain in the thoracic area is due to compression fractures resulting from osteoporosis. Osteoporosis is thinning and weakening of bone structure, most common in women after menopause. Thoracic Compression Fractures may result from an action which is non-traumatic, such as reaching up to place a dish in a cabinet. Other causes of Chronic Thoracic Pain include Thoracic Degenerative Disc Disease, Thoracic Spinal Stenosis, Thoracic Radiculopathy, Thoracic Disc Displacement and Post-Herpetic Neuralgia. Thoracic Pain can be difficult to treat and is often associated with difficulty breathing and muscle spasm.

The most common injury of the ankle is a sprain, which usually is not a long-term problem. Most chronic ankle problems are a result of trauma, such as fracture of the ankle. Sometimes the ankle may not heal correctly which may lead to chronic pain of the ankle. This can be exacerbated, obviously, by walking and made worse especially if the person is overweight, or if the ankle is weak, causing repeated ankle sprains, in addition to the underlying chronic ankle pain.

The human foot contains 28 bones. A fracture of any one of these bones is possible, but will usually heal over a period of time without intervention, other than limited weight-bearing. A fracture may cause osteoarthritis later in life. There are basically three possible causes of chronic pain in the foot. One is a previous crush injury, which causes severe osteoarthritis in the involved area.

The other cause of chronic foot pain is diabetic peripheral neuropathy (DPN) or simply peripheral neuropathy of unknown cause. Diabetic peripheral neuropathy, as the name implies, occurs in people who are diabetic. The severity and progression of DPN are unique to each individual, and the severity of disease does not always predict the severity of neuropathy. Nor do all diabetics develop neuropathy. Some people may have been diagnosed for many years with diabetes without experiencing DPN. There are also patients who develop neuropathy in the feet in which a cause cannot be identified. The pain of neuropathy is usually described as burning, prickly, "pins and needles" type pain, and is quite troublesome if the case is severe. The condition is irreversible.

The third major cause of foot pain is plantar fasciitis. The plantar fascia is a thick band of fibrous tissue located on the bottom of the foot, running from the heel to all five toes and connecting at the ball of the foot.This tissue may become inflamed and irritated and cause pain. The patient may also have a heel spur which is discovered on X-Ray, but despite what many people are told, heel spurs rarely cause pain. The spur forms as a result of constant stress caused by the plantar fascia pulling on the heel. A flattened arch is often a major contributor to this problem, so primary treatment should be aimed at correcting the arch. Plantar fasciitis can be completely cured in most patients, so it technically is not a chronic pain problem, however, it tends to resurface from time to time in those who are prone to it.

The most common causes of hand and wrist pain include carpal tunnel syndrome, Raynaud's phenomenon and fracture of the fingers, hand or wrist. Fractures will most likely lead to osteoarthritis in any of these areas later in life.

Carpal tunnel syndrome is a common occurrence, especially with the increased use of computers over the past decade, as well as other repetitive motions of the wrist. Carpal tunnel syndrome is cause by swelling and inflammation of the carpal tunnel in the wrist, the area through which the median nerve passes. When the area becomes inflamed, it swells, thus causing pressure on the nerve. The result is tingling, numbness and pain in the hand and fingers. Carpal tunnel release surgery is quite common and usually effective, but the condition often recurs after a period of time.

The third disorder that can cause chronic pain in the hand and fingers is Raynaud's phenomenon, or Raynaud's disease. This is a disorder of the vasculature (blood vessels) of the hand and fingers in which they become cold, many times with white then bluish discoloration and severe pain. An abnormal spasm of the blood vessels causes diminished blood flow to the area. Most of the time Raynaud's is precipitated by exposure to cold, such as cold weather or emotional stressors. When blood returns to the areas, there is a tingling sensation and the areas turn red. This condition may be related to a rheumatic disease, but can occur as a primary disease with no other disease associated with it.

Chronic pain of the elbow can many times be associated with repetitive motion injuries and cause "tennis elbow", "golfer's elbow", bursitis or epicondylitis. "Tennis elbow", or lateral epicondylitis, affects the outer portion of the elbow and "golfer's elbow", or medial epicondylitis, affects the inner portion of the elbow. The epicondyle is merely the prominent area of bone covering over the area where bone attaches to another bone by a tendon. Olecranon bursitis, inflammation of the tip of the elbow can result from infection (cellulitis), or chronic disease, such as gout or rheumatoid arthritis. Fractures may also occur in the elbow, which again, will likely result in the chronic pain of osteoarthritis.

Chronic Pain of the Knee usually occurs as a result of osteoarthritis of the knee, sometimes called degenerative joint disease. Osteoarthritis of the knee exists due to "wear and tear" of the knee joint over time, which is made worse in people who are over their ideal body weight, for obvious reasons. Luckily, total knee replacement surgery is successful in most cases, and after healing from surgery many patients are pain-free. One drawback to this surgery is that the artificial joint is estimated to last only 15-20 years and a person can only have one total knee replacement, hence only people who are of advanced age, whose life expectancy is 15-20 years or less are candidates for this surgery. With medical advancements, this will one day no longer be the case. One final note on knee replacement surgery--aggressive physical therapy is crucial immediately following the surgery so that the person may realize full range of motion (ROM) in the affected knee. Otherwise ROM will be limited for the duration of the person's life.

Another cause of chronic pain of the knee, mostly in younger people and especially athletes, is ligament damage, usually a tear of the ligament. In every case this does not progress to chronic pain, but it is a possibility, especially when the person continues the activities which caused the problem in the first place. Arthroscopic surgical repair is common, and the majority of the time results in full recovery of the torn ligament and cessation of the person's pain.

One other potential cause of chronic pain of the knee is a Baker's cyst. A Baker's cyst is benign and located in the concave area directly behind the knee. Sometimes needle aspiration of the cyst will take care of the problem, although surgical intervention is sometimes required. The only times a Baker's cyst would cause the pain to be chronic is if it recurs or if the patient chooses not to have it treated.

Other potential causes of chronic pain of the knee include trauma, such as a crushing injury or fracture of the patella (kneecap). Osteoarthritis will surely follow and cause chronic pain in any area where there has been a previous fracture.

Chronic Pain of the Shoulder may be caused by osteoarthritis, bursitis, tendonitis, frozen shoulder (adhesive capsulitis) or some type of rotator cuff injury. It is of the utmost importance that an accurate diagnosis be made so that the appropriate treatment may follow, hopefully leading to complete resolution of the problem, leaving the person without chronic pain.

The most common cause of chronic pain of the shoulder is osteoarthritis. This is usually the result of degeneration over time. For severe cases, the person may consider total shoulder replacement surgery, which, if successful, will restore function of the shoulder, but not necessarily take away all of the pain.

Frozen shoulder, or adhesive capsulitis occurs if the shoulder is immobilized for an extended period of time or sometimes it may occur for no identifiable reason at all. Just as the name implies, the shoulder becomes 'frozen' such that the range of motion is severely limited. Usually physical therapy will resolve frozen shoulder, but sometimes surgery is required. This condition does not always lead to chronic pain, however, it is a possibility.

The shoulder is the most flexible joint in the body, which is great because it gives us such a wide range of motion. Unfortunately, this same fact also causes it to be unstable and susceptible to injury.

Since there are so many different causes of Chronic Hip Pain, making a definitive diagnosis can sometimes be challenging. Making an accurate diagnosis is imperative, as the diagnosis will direct treatment of chronic hip pain.

Osteoarthritis is the most common cause of chronic hip pain. Conservative treatments are utilized initially, with total hip replacement being reserved for extremely severe cases, and usually in older patients.

Another cause of chronic hip pain is trochanteric bursitis, which is cause by inflammation of the covering of the hip joint, called the bursa. The word trochanteric comes from the portion of the hip called the greater trochanter.

Osteonecrosis is another condition that can cause chronic hip pain. Osteonecrosis occurs when blood flow to the bone of the hip is restricted. When blood flow to bone is inadequate, the bone cells die and the bone may collapse. While osteonecrosis may occur in any area of bone in the body, the hip is one of the most common areas of occurrence.

Another possible cause of chronic hip pain  is referred (radiating) pain from the lower back. The problem may result from a herniated disc, which causes sciatica, resulting in pain of the buttocks and hips.

Hip fractures also cause chronic hip pain, if left untreated, and are usually a result of trauma (fall) in elderly patients with osteoporosis. Surgical treatment is utilized to repair the hip, but pain usually continues, although not as severe as with the acute phase of the hip fracture.

Chronic Fibromyalgia Pain is a result of pain of the fibrous tissues of the body, such as tendons and ligaments, as well as the body's joints and muscles. The cause for this disease is unknown. It has been speculated that Fibromyalgia is an auto-immune disease, a disease in which the body senses itself as "foreign" and attacks it's own tissues, thus causing chronic pain.

The pain of Fibromyalgia is generalized, meaning it can manifest in many different areas of the body. Many Fibromyalgia patients state that the pain "moves" to different areas of the body--one day the middle back may hurt and the next day it could be the legs.

Fibromyalgia is difficult to treat and many health care providers remain skeptical that if even exists. Problems commonly associated with Fibromyalgia include insomnia and migraine headache, fatigue, anxiety, depression and numbness in the feet and hands.

While there is no diagnostic study for Fibromyalgia, it is usually diagnosed by palpation (using the fingers to depress the skin and soft tissue) of tenderness in certain areas of the body called "tender points". These tender points are located on each side of the body in exactly the same areas (bilaterally). They include: elbows, chest, buttocks, knees, neck, lower back, shoulders, rib cage and thighs.

Osteoporosis is closely related to chronic pain, because it can be a major contributor to several conditions that cause chronic pain. Prevention of osteoporosis is key and easily achievable for most, with the addition of dietary supplements to a nutritionally sound diet, and possibly a medication, when indicated.

Osteoporosis can contribute to vertebral fractures of the thoracic, cervical or lumbar spine. With osteoporosis, the bones become brittle and weakened, and as much as only a minor movement may cause the bones to collapse, causing a compression fracture. Compression fractures are difficult to treat and many times cause chronic pain.

Another medical problem osteoporosis contributes to in a major way is with hip fractures. The principle is the same as with vertebral fractures--the bone of the hip becomes weak and brittle. Osteoporosis often results in a hip fracture when there is some sort of trauma, usually a fall, and usually occurring in the elderly. While the acute fracture may be surgically repaired, chronic pain usually remains.