Understanding Arthritis: Causes, Symptoms, Diagnosis, and Treatment

Medically Reviewed by David Zelman, MD on June 30, 2023
10 min read

Arthritis is a broad term that covers a group of over 100 diseases. The word "arthritis" means "joint inflammation." Inflammation is one of your body's natural reactions to disease or injury. It includes swelling, pain, and stiffness. Inflammation that lasts a very long time or comes back, as in arthritis, can lead to tissue damage.

A joint is where two or more bones come together, such as the hip or knee.

The bones of your joints are covered with a smooth, spongy material called cartilage. It cushions the bones and allows the joint to move without pain.

The joint is lined by the synovium. The synovium's lining produces a slippery fluid -- called synovial fluid -- that nourishes the joint and helps limit friction within.

Outside it is a strong fibrous casing called the joint capsule. Strong bands of tissue, called ligaments, connect the bones and help keep the joint stable. Muscles and tendons also support your joints and allow you to move.

With arthritis, an area in or around a joint becomes inflamed, causing pain, stiffness, and sometimes, difficulty moving. Some types of arthritis also affect other parts of the body, such as the skin and internal organs.

About 1 in 5 adults has some form of arthritis. It can happen to anyone, but it becomes more common as you age.

Some of the more common types of arthritis are:

Osteoarthritis. This is the most common type. It causes the cartilage on the ends of your bones to wear away. That makes the bones rub against each other. You might have pain in your fingers, knees, or hips.

The cartilage breakdown, or degeneration, of osteoarthritis often happens with age. This is why osteoarthritis is sometimes called degenerative joint disease. But if there are other causes, it can begin much sooner. For example, an athletic injury like a torn anterior cruciate ligament (ACL) or a fracture near a joint can lead to arthritis. It can happen in any joint but most often affects the hands and weight-bearing joints such as the knee, hip, and facet joints (in the spine).

Rheumatoid arthritis. This long-lasting disease can affect joints in any part of the body but most often involves the hands, wrists, and knees. With rheumatoid arthritis, the immune system -- the body's defense system against disease -- mistakenly attacks the joints and causes the joint lining to swell. The inflammation spreads to the nearby tissues and can damage cartilage and bone. In more severe cases, rheumatoid arthritis can affect other areas of the body, such as the skin, eyes, and nerves.

Gout. This is a painful condition that happens when the body can't get rid of a natural substance called uric acid. The excess uric acid forms needle-like crystals in the joints that cause marked inflammation with swelling and severe pain. Gout most often affects the big toe, knee, and wrist joints.

The cause of many types of arthritis is unknown. Researchers are looking into the role of genetics (heredity) and lifestyle in the development of arthritis.

There are several things that may raise your risk for arthritis, including:

Age. Over time, your joints tend to get worn down. That's why the risk of developing arthritis, especially osteoarthritis, goes up with age.

Sex. Most types of arthritis are more common among women, except for gout.

Genes. Certain types of arthritis run in families. Conditions like rheumatoid arthritis, lupus, and ankylosing spondylitis, for example, are linked to certain genes.

Excess weight. Being overweight puts extra stress on weight-bearing joints, increasing wear and tear and the risk of arthritis, especially osteoarthritis.

Injuries. They can cause joint damage that can bring on some types of the condition.

Infection. Bacteria, viruses, or fungi can infect joints and trigger inflammation.

Work. Some jobs that use repetitive movements or heavy lifting can stress the joints or cause an injury, which can lead to arthritis, particularly osteoarthritis. For example, if you need to do a lot of knee bends and squats at work, you might be more likely to get osteoarthritis.

Different types of arthritis have different symptoms that can vary in severity from person to person. Osteoarthritis does not generally cause any symptoms outside the joint. Symptoms of other types of arthritis may include fatigue, fever, a rash, and signs of joint inflammation, including:

  • Pain
  • Swelling
  • Stiffness
  • Tenderness
  • Redness
  • Warmth
  • Joint deformity

A diagnosis of arthritis is the first step toward treatment. Your doctor will:

Consider your complete medical history. This will include a description of your symptoms. 

Do a physical exam. Your doctor will check for swollen joints, tenderness, redness, warmth, or loss of motion in the joints.

Use imaging tests like X-rays. These can often tell what kind of arthritis you have. X-rays are used to diagnose osteoarthritis, often showing a loss of cartilage, bone spurs, and in severe cases, bone rubbing against bone.

Test your joint fluid. Sometimes, joint aspiration (using a needle to draw a small sample of fluid from the joint for testing) and blood tests are used to tell osteoarthritis from other types.

If your doctor suspects infectious arthritis as a complication of some other disease, testing a sample of fluid from the affected joint will usually confirm the diagnosis and determine how it will be treated.

Test your blood or urine. These tests can help tell your doctor what type of arthritis you have or rule out other diseases as the cause of your symptoms.

Blood tests for rheumatoid arthritis include one for antibodies called rheumatoid factors (RF), which most people with rheumatoid arthritis have in their blood, though RF may also be present in other disorders.

A newer test for rheumatoid arthritis that measures levels of antibodies in the blood (called the anti-CCP test) is more specific and tends to be higher only in people who have or who are about to get rheumatoid arthritis. The presence of anti-CCP antibodies can also be used to predict which people will get more severe rheumatoid arthritis.

The goal of treatment is to provide pain relief, increase joint mobility and strength, and control the disease as much as possible. Your doctor has a number of options to help you manage pain, prevent damage to the joint, and keep inflammation at bay.

Treatment of arthritis could include rest, occupational or physical therapy, hot or cold compresses, joint protection, exercise, drugs, and sometimes surgery to correct joint damage. Your treatment plan may involve more than one of these.

Treatments for osteoarthritis generally can help relieve pain and stiffness, but the disease may continue to get worse. The same was true for rheumatoid arthritis in the past, but treatments are now able to slow or stop the progression of arthritis damage.

Protecting your joints is an important part of arthritis treatment. With the help of an occupational therapist, you can learn easier ways to do your normal activities. An occupational therapist can teach you how to:

  • Avoid positions that strain your joints
  • Use your strongest joints and muscles while sparing weaker ones
  • Provide braces or supports to protect certain joints
  • Use grab bars in the bath
  • Use modified doorknobs, canes, or walkers
  • Use devices to help you with tasks such as opening jars or pulling up socks and zippers

Arthritis treatment will depend on the nature and seriousness of the underlying condition. The main goals are to reduce inflammation and improve the function of affected joints before more serious problems occur.

To reduce pain and inflammation of rheumatoid arthritis and osteoarthritis, your doctor will probably prescribe acetaminophen or a nonsteroidal anti-inflammatory drug (NSAID).

If you're making decisions about drugs for arthritis pain relief, you may want to ask your doctor:

  • Which pain medication is best for me right now?
  • Is it safe to take this drug every day?
  • How long will I need to take this medication? Is it a short-term or long-term treatment?
  • When can I expect to see improvement in my arthritis pain?
  • Will this pain medicine interact with other medications I'm taking?
  • What potential side effects should I know about with this drug?
  • What can I do to decrease the risk of side effects?
  • What should I do if I have flare-ups of pain while taking this medication?
  • Is there anything else I can do to relieve my pain?

In addition to painkillers, your doctor may recommend corticosteroid joint injections to ease the pain and stiffness of affected joints. Results range from temporary to long-lasting relief.

Additional drugs that may help preserve joint function in people with rheumatoid arthritis include:

In general, these medications work by suppressing the overactive immune system.

Treatment of infectious arthritis typically involves large intravenous doses of antibiotics, as well as drainage of excess infected fluid from the joints.

Various forms of surgery may be needed to reduce the discomfort of arthritis or to restore mobility or joint function. Synovectomy is the removal of damaged connective tissue lining a joint cavity.

If arthritic pain and inflammation become truly unbearable, or arthritic joints become so damaged, the answer may lie in surgical replacement. Today, knee and hip joints can be replaced with reliable artificial joints made of stainless steel, plastic, and ceramic materials. Shoulder joints, as well as smaller joints in the elbows and fingers, can also be replaced.

Spinal surgery is sometimes performed for neck and lower spine arthritis. Although movement is limited after such surgery, the operations relieve excruciating pain and help prevent further damage to nerves or blood vessels.

Aside from medical treatments for arthritis, there are effective psychotherapeutic strategies to manage arthritic pain. The National Institutes of Health (NIH) has found that cognitive behavioral therapy, using education and behavior modification alongside relaxation techniques, is better than routine care for relieving pain associated with arthritis.

Such programs focus on improving patients' emotional and psychological well-being by teaching them how to relax and conduct their daily activities at a realistic pace. Learning to overcome mental stress and anxiety can be the key to coping with the physical limitations that may accompany chronic rheumatoid arthritis and osteoarthritis.

Cognitive therapy may include various techniques for activity scheduling, imaging, relaxation, distraction, and creative problem-solving.

A variety of alternative therapies is used for arthritis. However, none of these has been approved by the FDA for the treatment of arthritis, so they may not be effective or safe. It is important to let your doctor know if you're considering these types of treatments.

While some studies suggest that glucosamine and chondroitin supplements are as effective as NSAIDs for reducing pain, swelling, and stiffness in osteoarthritis, recent large studies funded by the NIH suggest these supplements are not very helpful, except perhaps in some cases. Typical daily doses are 1,500 milligrams for glucosamine and 1,200 milligrams for chondroitin.

The antibiotic doxycycline may have some potential to delay the progression of osteoarthritis by inhibiting enzymes that break down cartilage. More research is needed to confirm these results.

The NIH considers acupuncture an acceptable alternative treatment for osteoarthritis, especially if it affects the knee. Studies have shown that acupuncture helps reduce pain, may significantly lessen the need for painkillers, and can help increase range of motion in affected knee joints.

The supplement SAMe has been shown in some studies to be as effective for osteoarthritis pain as NSAIDs.

Fish oil has been shown to reduce inflammation, lessen the need for painkillers, and possibly decrease joint stiffness. A diet low in animal and dairy fats may have similar effects. Excellent sources of fish oil include EPA/DHA capsules and oily fish such as salmon and mackerel.

At least a dozen herbs have been used to ease the symptoms of both osteoarthritis and rheumatoid arthritis. Ask your doctor about using any herbs, since they can interact with each other or with medication you are taking. Herbs that have been used are powdered ginger, borage seed oil, and devil's claw to reduce pain and swelling. Stinging nettles and turmeric have also been used.

Ayurvedic medicine uses herbal compounds internally and externally for arthritis symptom relief. Topical curcumin may help relieve the inflammation of rheumatoid arthritis; if taken in capsule form, it can reduce morning stiffness and boost endurance. In one study, a combination of Withania somnifera, Boswellia serrata, and Cucurma longa caused a significant drop in pain and disability for people with osteoarthritis.

In addition to treatments recommended by your doctor, you can use dry heat from a heating pad or moist heat in the form of a hot bath or a hot-water bottle wrapped in a towel to help relieve pain and stiffness. Heat and rest are very effective in the short run for most people with the disease. Regular exercise is also important to keep the joints mobile.

If you are overweight, losing weight is key, especially when arthritis affects the lower back, knees, and legs. Extra pounds add to the load and pressure on your joints, which can cause your arthritis to get worse faster. Being overweight also raises your chances of related health problems. Consult a registered dietitian who can help you plan a healthy weight loss program.

People with weakened, badly deformed fingers from rheumatoid arthritis benefit from specially designed utensils and door and drawer handles; people with weakness in the legs and arms can use special bathroom fixtures, especially tub rails and elevated toilet seats.

Although arthritis may not be preventable, disability is -- with a well-designed treatment program, including medications, exercise, and physical therapy when needed.

Here are some more things you can do to help keep the condition in check:

Educate yourself. Take a self-management course to learn specifics on day-to-day arthritis care.

Get active. Exercise can help you move better, lessen pain, and put off disability.

Use joint-protecting devices and techniques at work. Proper lifting and posture can help protect your muscles and joints.

Eat a healthy diet. A well-balanced, nutritious diet can help strengthen your bones and muscles.

Don't put off treatment. The sooner you're treated, the more likely you are to avoid permanent joint damage.

With early diagnosis, most types of arthritis can be managed and the pain and disability minimized. In addition, early diagnosis and treatment may be able to prevent tissue damage caused by arthritis. Early, aggressive treatment is particularly important for rheumatoid arthritis in order to help prevent further damage and disability down the road.