Arthritis means joint inflammation, but the term is used to describe more than 100 conditions that affect joints, the tissues that surround the joint, and other connective tissues. The causes of arthritis vary depending on the type.

The most common form of arthritis is osteoarthritis. Other common rheumatic conditions types of arthritis include gout and rheumatoid arthritis (RA).

Arthritis affects 58.5 million adults in the United States, which equals about 1 in 4 people. It is more common among adults aged 65 years or older. However, it can affect people of all ages, including children.

This article discusses the different types of arthritis, what causes it, and possible treatments.

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Arthritis refers to more than 100 rheumatic diseases and conditions that affect joints. These conditions tend to involve pain, aching, stiffness, and swelling in and around one or more joints.

The word “arthritis” means “joint inflammation.” However, inflammation may also affect the tendons and ligaments surrounding the joint. The symptoms can develop gradually or suddenly and may impair a person’s ability to perform everyday tasks.

There are more than 100 types of arthritis. Generally, arthritis can be split into the following categories:

Inflammatory arthritis

Inflammation is a normal part of the body’s healing process. It tends to occur as a defense against viruses and bacteria or as a response to injuries such as burns. However, with inflammatory arthritis, inflammation occurs in people for no apparent reason.

Inflammatory arthritis is characterized by damaging inflammation that does not occur as a normal reaction to injury or infection. This type of inflammation is unhelpful and instead causes damage to the affected joints, resulting in pain, stiffness, and swelling.

Inflammatory arthritis can affect several joints, and the inflammation can damage the surface of the joints and also the underlying bone.

Examples of inflammatory arthritis include:

Degenerative or mechanical arthritis

Degenerative or mechanical arthritis refers to a group of conditions that mainly involve damage to the cartilage that covers the ends of the bones.

The main job of the smooth, slippery cartilage is to help the joints glide and move smoothly. This type of arthritis causes the cartilage to become thinner and rougher.

To compensate for the loss of cartilage and changes in joint function, the body begins to remodel the bone in an attempt to restore stability. This can cause undesirable bony growths to develop, called osteophytes. The joint can become misshapen. This condition is commonly called osteoarthritis.

Osteoarthritis can also result from previous damage to the joint such as a fracture or previous inflammation in the joint.

Connective tissue disease (CTD)

Connective tissues support, bind together, or separate other body tissues and organs. They include tendons, ligaments, and cartilage.

CTD involves joint pain and inflammation. The inflammation may also occur in other tissues, including the skin, muscles, lungs, and kidneys. This can result in various symptoms besides painful joints, and it may require consultation with a number of different specialists.

Examples of CTD include:

  • SLE, or lupus
  • scleroderma, or systemic sclerosis
  • dermatomyositis
  • Sjogren’s

Infectious arthritis

A bacterium, virus, or fungus that enters a joint can sometimes cause inflammation.

Organisms that can infect joints include:

A doctor can treat a joint infection with antibiotics or other antimicrobial medication. However, the arthritis can sometimes become chronic, and joint damage may be irreversible if the infection has persisted for some time.

Metabolic arthritis

Uric acid is a chemical created when the body breaks down substances called purines. Purines are found in human cells and several foods.

Most uric acid dissolves in blood and travels to the kidneys. From there, it passes out of the body in urine. Some people have high uric acid levels because they either naturally produce more than they need or their body cannot clear the uric acid quickly enough.

Uric acid builds up and accumulates in some people and forms needle-like crystals in the joint, resulting in sudden spikes of extreme joint pain or a gout attack.

Gout can either come and go in episodes or become chronic if uric acid levels are not reduced.

It commonly affects a single joint or a small number of joints, such as the big toe and hands. It usually affects the extremities. One theory is that uric acid crystals form in cooler joints, away from the main warmth of the body.

Some of the more common types of arthritis are discussed below.

Childhood arthritis

This can refer to a number of types of arthritis. Juvenile idiopathic arthritis (JIA), also known as juvenile rheumatoid arthritis (JRA), is the most common type.

Arthritis in childhood can cause permanent damage to joints, and there is no cure. However, remission is possible, during which time the disease remains inactive.

It may be due to immune system problems.

Septic arthritis

Septic arthritis is a joint inflammation that results from a bacterial or fungal infection. It commonly affects the knee and hip. It typically affects 2-6 people per 100,000.

It may develop when bacteria or other disease-causing microorganisms spread through the blood to a joint, or when the joint is directly infected with a microorganism through injury or surgery.

Bacteria such as Staphylococcus, Streptococcus, or Neisseria gonorrhoeae cause most cases of acute septic arthritis. Organisms such as Mycobacterium tuberculosis and Candida albicans cause chronic septic arthritis. This is less common than acute septic arthritis.

The following conditions increase the risk of developing septic arthritis:

  • existing joint disease or damage
  • artificial joint implants
  • bacterial infection elsewhere in the body
  • presence of bacteria in the blood
  • chronic illness or disease (such as diabetes, RA, and sickle cell disease)
  • intravenous (IV) or injection drug use
  • medications that suppress the immune system
  • recent joint injury
  • recent joint arthroscopy or other surgery
  • conditions such as HIV, that weaken immunity
  • diabetes
  • older age

Septic arthritis is a rheumatologic emergency as it can lead to rapid joint destruction. It can be fatal.

The symptoms of arthritis that appear and how they appear vary widely, depending on the type.

They can develop gradually or suddenly. As arthritis is most often a chronic disease, symptoms may come and go, or persist over time.

However, anyone who experiences any of the following four key warning signs should see a doctor.

  1. Pain: Pain from arthritis can be constant, or it may come and go. It may affect only one part or be felt in many parts of the body.
  2. Swelling: In some types of arthritis, the skin over the affected joint becomes red and swollen and feels warm to the touch.
  3. Stiffness: Stiffness is a typical symptom. With some types, this is most likely upon waking up in the morning, after sitting at a desk, or after sitting in a car for a long time. With other types, stiffness may occur after exercise, or it may be persistent.
  4. Difficulty moving a joint: If moving a joint or getting up from a chair is hard or painful, this could indicate arthritis or another joint problem.

In addition to these general signs, certain types of arthritis may cause their own unique symptoms. For example, Juvenile RA can cause eye problems, including uveitis, iridocyclitis, or iritis.

Septic arthritis often causes fever and intense joint pain. It can become an emergency if it progresses to sepsis.

There is no single cause of all types of arthritis. The cause or causes vary according to the type or form of arthritis.

Possible causes may include:

  • an injury, which can lead to degenerative arthritis
  • an abnormal metabolism, which can cause gout and calcium pyrophosphate deposition disease (CPPD)
  • a genetic inheritance, which can lead to developing osteoarthritis
  • an infection such as Lyme disease, which can trigger arthritis symptoms
  • an immune system dysfunction, such as the type that causes RA and lupus

Most types of arthritis are linked to a combination of factors. However, some have no obvious cause and appear to be unpredictable in their emergence.

Treatment for arthritis aims to control pain, minimize joint damage, and improve or maintain function and quality of life. A range of medications and lifestyle strategies can help achieve this and protect joints from further damage.

The exact treatment depends on the type of arthritis a person develops. It may involve:

Medication

Medications will depend on the type of arthritis. Commonly used drugs include:

  • Analgesics: These reduce pain. However, they have no effect on inflammation. Examples include acetaminophen (Tylenol) and tramadol (Ultram).
  • Nonsteroidal anti-inflammatory drugs (NSAIDs): These reduce both pain and inflammation. NSAIDs include available to purchase over-the-counter or online, including ibuprofen (Advil, Motrin IB) and naproxen sodium (Aleve). Some NSAIDs are available as creams, gels, or patches, which can be applied to specific joints.
  • Counterirritants: Some creams and ointments contain menthol or capsaicin, the ingredient that makes hot peppers spicy. Rubbing these on the skin over a painful joint can modulate pain signals from the joint and lessen pain.
  • Disease-modifying antirheumatic drugs (DMARDs): These are used to treat RA. DMARDs slow or stop the immune system from attacking the joints. Examples include methotrexate (Trexall) and hydroxychloroquine (Plaquenil).
  • Biologics: These are genetically engineered drugs that target various protein molecules involved in the immune response. Examples include etanercept (Enbrel) and infliximab (Remicade).
  • Corticosteroids: prednisone and cortisone reduce inflammation and suppress the immune system.

Natural remedies

A healthful, balanced diet, along with appropriate exercise and avoidance of smoking and drinking too much alcohol can help people with arthritis maintain their overall health and reduce symptom severity.

Diet

Eating some types of food may help reduce inflammation.

The following foods, found in a Mediterranean diet, can provide many nutrients that are good for joint health and can help relieve joint inflammation.

  • fish
  • nuts and seeds
  • fruits and vegetables
  • beans
  • olive oil
  • whole grains

On the other hand, people living with arthritis should avoid or limit eating processed foods, foods that contain added sugar, and refined carbohydrates. These foods may actually make arthritis inflammation worse.

Learn more about diet and arthritis.

Physical therapy and exercise

Doctors will often recommend a course of physical therapy to help patients with arthritis overcome some of the challenges and to reduce limitations on mobility.

Forms of physical therapy that may be recommended include:

  • Physical therapy: specific exercises tailored to the condition and individual needs, sometimes combined with pain-relieving treatments such as ice or hot packs and massage
  • Occupational therapy: practical advice on managing everyday tasks, choosing specialized aids and equipment, protecting the joints from further damage, and managing fatigue

In addition, although individuals with arthritis may experience short-term increases in pain when first beginning exercise, continued physical activity can effectively reduce long-term symptoms.

People with arthritis can participate in joint-friendly physical activity on their own or with friends. As many people with arthritis have other conditions, such as heart disease, it is important to choose appropriate activities.

Joint-friendly physical activities that are appropriate for adults with arthritis and heart disease include:

  • walking
  • swimming
  • cycling

A healthcare professional can help you find ways to live a healthful lifestyle and have a better quality of life.

Herbal medicines

A number of natural remedies have been suggested for different types of arthritis. Research has shown that some herbal supplement may be able to relieve some pain and inflammation or help reduce the need for taking pain medications. These include:

  • Devil’s claw
  • Boswellia
  • chamomile
  • turmeric
  • ginger

However, anyone considering using natural remedies for any type of arthritis should speak to a doctor first.

Surgery

Depending on the type of arthritis a person has, different surgical treatments on the affected joints may be necessary. It may depend on the degree of a person’s symptoms and whether other treatments have been successful.

Surgery options for arthritis include:

  • synovectomy
  • total joint replacement (TJR)
  • osteotomy
  • joint fusion

Learn about these and other surgical treatments for arthritis.

There are more than 100 types of arthritis.

Some types, such as RA and lupus, are caused by an overactive immune system and affect multiple organs. Other types are caused by physical degeneration in specific joints.

Factors in the development of arthritis include:

  • injury
  • abnormal metabolism
  • genetic makeup
  • infections
  • immune system dysfunction

A doctor can help a person determine whether they have arthritis and the best course of treatment for them. Treatments can include medications and lifestyle changes. In some cases, a person may need surgery.