Arthritis: What are the most common forms of arthritis?

Inflammation and pain in the joints, or arthritis, can be caused by many things. The CDC estimates about 23% of all adults have been diagnosed with some form of it. In fact, 12% of people in the USA suffer with arthritis chronically. According to the Arthritis Foundation, there are over a hundred different forms of arthritis and related diseases. Psoriasis, bacterial infections (e.g., gonorrhea), viral infections (e.g., hepatitis B, Chikungunya), lupus, scleroderma, Lyme disease, bursitis, fibromyalgia, and gout can all cause arthritis, making diagnosis challenging.
Arthritis has a severe economic impact due to lost employment days and lost wages and a psychological impact due to its negative influence on quality of life. Untreated, it can only get worse, resulting in permanent joint damage and a lifelong ordeal of suffering.

What are the most common forms of arthritis?

The top two types of arthritis, comprising 90% of all arthritis diagnoses, are osteoarthritis, which is known as a degenerative joint disease, and rheumatoid arthritis, which is an autoimmune disease. Osteoarthritis makes up 80% of all arthritis diagnoses, while rheumatoid arthritis comprises 10%. The other 10% is made up of psoriatic arthritis and the other myriad forms of arthritis.

What are the symptoms of arthritis?

The symptoms of OA and RA are similar, as they share inflammation, swelling, and pain of the joints as some of their side effects. However, they are vastly different in terms of where they, and by extension, their side effects, develop on the body.

Osteoarthritis (OA)

This is the most common form of arthritis. It is simply inflammation tied to wear and tear and occurs most commonly in the hands, hips, and knees. Osteoarthritis develops when the cartilage and bones begin to break down and result in the deterioration of the cushioning between the joints. By the age of 75, more than 80% of people will experience this form of arthritis. Advanced age, obesity, hereditary factors, gender (women are more likely to experience it than men), bone density, trauma, and lack of exercise are all risk factors for osteoarthritis and can make it worse when present.
OA can either be localized or generalized. The age of onset for this condition typically occurs after 40. It typically begins in the hands and then goes to the knees, and the other joints follow over the years. OA is characterized by hard swellings of the finger joints, which are called Heberden’s nodes when they occur in the distal finger and Bouchard’s nodes when they occur in the middle of fingers. The two types of osteoarthritis are the following:

  • Localized: Localized OA affects only one joint.
  • Generalized: This is OA of several joints, which are usually the distal finger joints and the cervical, lumbar, hip, and knee joints in various assortments. The list of joints affected, and the severity of the OA grows over the years.

Rheumatoid arthritis (RA)

In rheumatoid arthritis (RA), one’s own immune system attacks the joints. It is a symmetric, multi-joint, and deformative type of arthritis, and it occurs more in women than men (3:1).

How is arthritis diagnosed?

  • History and physical exam: The types of joints involved with arthritis complaints can be the first indicator of whether the arthritis involved in OA or RA. Distal finger joints, neck, lumbar, and knees are typical sites of OA and begin in a localized presentation. RA is typically polyarticular and is associated with symmetrical involvement of the distal joints. Heberden’s and Bouchard’s nodes can be understood as indicating OA instead of RA as can complaints of central areas, like the back and neck.
  • X-Rays: This is the most common method of evaluating arthritis. Osteophytes, narrow joint spaces, and cysts can be seen with OA, but with RA, there is also erosion and deformity.
  • MRI: MRIs are generally not well-suited for detecting OA, although it can be useful in detecting its early stages. MRIs re better for seeing bone erosions in RA.
  • Ultrasound: This can detect inflammation, fluid, and osteophytes. It is useful in both OA and RA.
  • Blood work: In the majority of people with RA, a rheumatoid factor (RF) can be identified. Neither its presence or absence rule in or rule out RA, but its presence adds to the suspicion or corroborates a suspicion of RA. An elevated peptide test, anti-cyclic citrullinated peptide (CCP) test, C-reactive protein (CRP) test, and erythrocyte sedimentation rate (ESR) test can also raise suspicion about the presence of RA.
  • Joint fluid aspiration: Examining the fluid taken from around a joint can be helpful in ruling out other forms of arthritis.

How is arthritis treated?

The treatment of arthritis depends on the type of arthritis.

Treatment of OA

  • Holistic approach: Since OA is a wear-and-tear degeneration of the joint cartilage and other aspects of bone juxtaposition, treatment should be tailored to the patient holistically. Aggravating factors, such as obesity, lack of exercise, smoking, and repetitive motion injury, should be targeted first.


  • Topical NSAIDs
  • Oral NDAIDs
  • Topical duloxetine (Cymbalta): This treatment can be used when NSAIDs are contraindicated, such as with gastritis or clotting problems.
  • Topical capsaicin: This is a pepper that overwhelms the pain mechanism. It may cause a burning sensation as its side effect.
  • Injection with steroids: This is only a temporary form of treatment, so its routine use is discouraged.


  • These are discouraged due to abuse and addiction potential.


  • When there is joint destruction to the point of crippling, joint replacement is beneficial if all other remedies have proven ineffective.

Treatment of RA

Care by a specialist in RA, such as a rheumatologist, gives better outcomes.


  • Education, rest and exercise, physical therapy, dietary counseling, and immunizations decrease the risk that is necessary with immunosuppressive therapies.


  • Since drug treatment for RA targets the immune system, all patients should be screened for infectious diseases, such as hepatitis, TB, etc. Common approaches to RA include the following:
    • Steroids
    • NSAIDs
    • Disease modifying antirheumatic drugs (DMARDs):
    • There are non-biologic DMARDs, such as methotrexate.
    • Biologic DMARDs are a category of treatments derived from molecular biologic techniques and target specific steps in the inflammatory process. These DMARDs work faster than the non-biologic ones, but they must be given by injection.


  • When there is joint destruction to the point of crippling, or if there is pending tendon rupture, surgery may be necessary.

Arthritis is a generic word that simply refers to inflammation of a joint. There are many types of arthritis, and each is a different disease that requires different diagnostic techniques and different treatments. Of all the arthritis categories, the two major ones are the osteoarthritis and rheumatoid arthritis. OA will come to everyone, while RA will develop in only one of 2,500 persons. For each, early detection and intervention will slow their progress and help prevent the crippling effects that each can cause.