Arthritis: Making the Diagnosis

There are more than 100 types of arthritis, so when it comes to diagnosis the first challenge is to determine the cause of the inflammation.


Inflammatory arthritis is an umbrella term for a group of autoimmune disorders in which the primary disease process is inflammation

© One Photo |

Once your medical history, physical examination, and diagnostic tests have been evaluated, your medical provider may diagnose you with one of the following types of arthritis. It also is possible that you may be diagnosed with a multisystem disorder.

Degenerative Arthritis

OA is the main cause of degenerative arthritis. It can affect any joint but typically impacts those that experience the most repetitive stress, such as the hips, knees, spine, shoulders, and hands. OA was once thought to be primarily a disease caused by normal wear and tear from years of usage. However, accumulating research suggests that the underlying cause may be chronic inflammation, which makes the joint more susceptible to the aging process.

OA usually presents with pain, morning stiffness (less than 30 minutes), and minimal soft-tissue swelling. The individual usually feels otherwise well (at least early on). ESR and CRP tests are often normal. Early x-rays may be normal, but over time, bony outgrowths and irregular joint narrowing can develop.

When degenerative disease does not involve the finger or thumb joints, hips, and knees, other causes may be at play, including osteonecrosis (diminished blood supply to the bones) and Charcot arthropathy (progressive deterioration of a joint due to nerve damage), both of which are rare and will not be discussed further in this report.

Inflammatory Arthritis

Inflammatory arthritis is an umbrella term for a group of autoimmune disorders in which the primary disease process is inflammation. Rheumatoid arthritis is probably the most well-known example—other types include psoriatic arthritis, and ankylosing spondylitis.

When more than three joints are involved, RA is the most likely cause, with the hands inevitably affected. RA presents with pain and morning stiffness that may last for hours, along with marked soft-tissue swelling. The individual may feel unwell during a flare-up. Blood tests may be positive for RF in 60 to 70 percent of cases—ESR and CRP also may be raised. X-rays may show bone erosion, and deformities of the fingers.

Metabolic Arthritis

Metabolic arthritis can be difficult to diagnose. It usually presents with an acute episode of pain and swelling, often in one joint, that may recur and occasionally become chronic. The symptoms are the result of minute needle-sharp crystals depositing in the joint.

The most common type of metabolic arthritis is gout, which is caused by a build-up of uric acid crystals due to hyperuricemia (high uric acid levels in the blood). Gout typically presents as a sudden onset of severe pain, swelling, and inflammation of a joint, often the metatarsal-phalangeal joint of the big toe. Other sites that may be affected by gout include the arch of the foot, ankle, knee, fingers, and wrist. In early gout, only one or two joints are involved.

Blood and urine tests are unreliable when it comes to diagnosing gout, since many people with hyperuricemia do not develop gout and some people with the condition do not have hyperuricemia. If necessary, the diagnosis can be confirmed by examining the synovial fluid for the presence of uric acid crystals.

A condition called pseudogout causes similar symptoms to those of gout, but is caused by a buildup of calcium pyrophosphate crystals in the joint.

Infectious Arthritis

Blood tests, urine tests, and joint aspiration are useful in reaching a diagnosis of infectious arthritis. There are two main types of infectious arthritis:

  • Reactive arthritis (ReA) is inflammation of joints caused by infection in another body system (such as genital, urinary, or gastrointestinal) that spreads to the joint. It can occur as an acute or chronic arthritis. ReA may affect any number of joints and is usually asymmetrical.
  • Septic arthritis is a primary infection within the joint due to bacteria, viruses, and fungi. The infection is usually introduced into the joint during a medical procedure or surgery, and only one joint is involved. This is a serious condition requiring immediate antibiotic therapy in a hospital setting.

Multisystem Disorders

Several conditions cause joint pain and generalized inflammation and may mimic arthritis.

  • Fibromyalgia is a common, chronic disorder presenting with widespread pain, stiffness and tenderness around the joints. Fatigue, cognitive difficulties, anxiety, and depression also may occur.
  • Lupus (systemic lupus erythematosus) may mimic RA, with accompanying skin and internal organ involvement. Lupus diagnosis is based on clinical presentation and blood tests.
  • Scleroderma may cause swelling and tenderness that mimics RA, with accompanying poor circulation in the hands and feet (called Raynaud’s phenomenon), and progressive hardening of the skin. Scleroderma is caused by excessive production and deposition of collagen (a protein that forms connective tissue in the skin, blood vessels, and internal organs), and the disease also may affect internal organs (gastrointestinal, lungs, and heart). Diagnosis is based on clinical symptoms, inflammatory and antibody blood tests, and investigations on the internal organs affected.
  • Ankylosing spondylitis is a chronic, multisystem inflammatory disorder. It mainly affects the vertebrae and sacroiliac joints (where the spine and pelvis join), but also may involve the hands and feet, tendons and ligaments, and other organs. Diagnosis depends on clinical criteria and radiological findings.
  • Sjögren’s syndrome is an autoimmune disease that attacks the joints, eyes, mouth, salivary glands, and, rarely, internal organs. Common symptoms include dry eyes, a dry mouth, swollen salivary glands, and joint pain. Blood tests for inflammation and antibodies are useful, but a positive biopsy of salivary glands gives a conclusive diagnosis.

For more information on arthritis symptoms and treatment, purchase Arthritis Guide to Diagnosis and Treatment at

As a service to our readers, University Health News offers a vast archive of free digital content. Please note the date published or last update on all articles. No content on this site, regardless of date, should ever be used as a substitute for direct medical advice from your doctor or other qualified clinician.

Tags: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , ,

Leonaura Rhodes, MD

Dr. Leonaura Rhodes is a physician turned author, coach, and freelance medical writer and editor. She has worked for Belvoir Media since 2017 and has authored hundreds of articles on … Read More

View all posts by Leonaura Rhodes, MD

Enter Your Login Credentials
This setting should only be used on your home or work computer.