Arthritis and related diseases are major causes of debilitating, life-changing pain for many Americans. A May 2010 report issued by the Centers for Disease Control and Prevention notes that among adults with arthritis, 37.7 percent report that arthritis causes limitations on their activities, 31.2 percent say it leads to work limitation, and 25.6 percent note that it causes severe pain (seven or higher on a zero to 10 point scale).

There are more than 100 different forms of arthritis and related diseases, but the most prevalent types include osteoarthritis (OA), rheumatoid arthritis (RA), fibromyalgia and gout. All of these conditions can cause pain, but they do so differently.

Here’s a quick overview of the types of pain you are likely to experience if you’ve been diagnosed with one of these conditions, as well as look at the drugs most often used to treat both symptoms and the underlying cause.

Osteoarthritis

In osteoarthritis (OA), joint components like cartilage, a rubber-like material that cushions bones as they move around in the joint, or synovial fluid, which lubricates the joint so bones can move more easily, deteriorate due to years of use, injuries and processes within the body.

As these protective substances break down, movement becomes more difficult and painful. In time, bones may rub directly against one another inside the joint, causing severe pain. Inflammation can also result from this constant, painful friction in the joints, so people with OA often take regular doses of nonsteroidal anti-inflammatory drugs (NSAIDs) to reduce the inflammation and ease pain. In addition, many people with OA take analgesics to ease pain, including acetaminophen or, if pain is severe, an analgesic combined with an opioid, such as codeine or hydrocodone.

OA often affects joints like knees, hips, feet, hands and fingers, wrists, neck and the spinal cord. Typically, OA does not affect the same joint on both sides of the body – such as both knees – but this can occur in some people. OA pain levels vary greatly. Pain can range from mild to moderate and be manageable with drugs and regular physical activity. Or it can be so debilitating that any movement or pressure at all on the affected joints becomes nearly impossible. In severe cases, surgery to replace the damaged joint may be the only effective treatment.

Rheumatoid Arthritis

Rheumatoid arthritis (RA) pain is usually caused at first by a severe inflammation in the joints. This inflammation doesn’t result from joint components rubbing together as in OA, but from a malfunction in the body’s immune system.

Normally, the immune system responds to injury or illness by triggering temporary inflammation. This inflammation lets you know that there’s a problem and that you should treat the issue or rest the injured joint. In RA, the immune system goes awry and turns against healthy tissues. The inflammation is chronic rather than temporary.

Over time, the persistent inflammation not only causes pain, it breaks down the joint and damages it permanently. RA inflammation can also affect internal organs like the liver, heart, spleen and eyes. When RA affects children, it is called juvenile idiopathic arthritis. This disease can be particularly severe and damaging to young joints.

People with RA often have flares of pain, or sudden onsets of severe inflammation that may last for days or weeks. To treat RA pain, doctors often prescribe drugs to stop the malfunctioning inflammatory response. These medications include disease-modifying antirheumatic drugs (DMARDs) which, as the name implies, halt the processes that cause inflammation and biologic response modifiers (biologics), a subset of DMARDs that work at the cellular level. By stopping the body’s out-of-control inflammation, the pain can be controlled. People with RA may also take NSAIDs or analgesics in addition to the disease-modifying drugs that address their immune system problems.

Fibromyalgia

Unlike other arthritis-related diseases that involve damage to or disease within the joints, fibromyalgia pain affects the body’s soft tissues, including muscles, rather than the bones and joints.

Originally, fibromyalgia mystified doctors because they couldn’t see any physical evidence of disease or injury in the painful joints. In time, research showed that people with fibromyalgia may have imbalanced levels of certain chemicals in their bodies, including serotonin. These substances may cause the brain to sense pain more intensely, or interfere with the person’s ability to sleep deeply, leading to a reduced ability to recover and an increased sensitivity to pain.

People with fibromyalgia sense pain in and around areas of the body called tender points. At these sensitive spots, often near joints, increased sensitivity to stimuli and intense, aching pain can occur. To address fibromyalgia pain, doctors often prescribe drugs to address imbalances in serotonin or other key neurochemicals. Drugs for treating fibromyalgia pain include antidepressants like selective serotonin re-uptake inhibitors (SSRIs), and anticonvulsant drugs like pregabalin (Lyrica), the first drug specifically approved to treat fibromyalgia pain.

Gout

Most form of arthritis pain develop and intensify slowly over time. With gout, however, you can go to bed feeling fine and wake up with excruciating pain and tenderness. Gout usually strikes in the large joint of the big to, but can also affect other joints such as the feet, ankles, knees, elbows, hands, wrists, elbows and sometimes even soft tissues and tendons.

Gout pain results from a condition called hyperuricemia, which simply means you have a high level of uric acid in the blood. Uric acid forms when the body breaks down waste products called purines, which are found in plant- and animal-based foods. Some people’s bodies produce an excess of uric acid; other people don’t overproduce too much acid, but their kidneys can’t eliminate the amount they do produce quickly enough.

When uric acid isn’t eliminated, it can form crystals in the fluid that lubricates joint linings, and that results in painful joint swelling and inflammation. If gout goes untreated, these crystals can form tophi – lumps in the affected joints or surrounding tissues.  

Treating gout is a two-pronged effort – first control the pain and inflammation of the current attack, usually with NSAIDs, corticosteroids or a plant-derived drug called colchicine (Colcrys). Once your gout attack subsides, usually within days, your doctor will prescribe one of several medications designed to control uric acid levels. Making lifestyle changes, such as drinking more water, less alcohol and avoiding purine-rich foods, can also help prevent future gout attacks.

Other Arthritis-Related Diseases:

There are many forms of arthritis and related diseases that cause joint pain. Other types include ankylosing spondylitis, which typically affects the spine and the joints of the pelvis; polymyalgia rheumatica, a condition often triggered by inflammation in the blood vessels that leads to joint pain and swelling; and soft-tissue rheumatic conditions like tendinitis and bursitis, where connective tissues and cushioning joint components become inflamed and painful.

In many of these conditions, doctors either try to stop the cause of the inflammation with DMARDs, or control inflammation with NSAIDs. In all cases, people with severe pain due to an arthritis-related condition may also try analgesic drugs.

OA

NSAIDs

Analgesics

Surgery

Inflammation

DMARDs

Biologics

Fibro drugs

Gout

Gout drugs

Sources:

See Causes of Pain story.