Arthritis Diagnosis

Diagnosing arthritis can be confusing and complicated. With over 100 types of arthritis and rheumatic diseases, symptoms—especially early symptoms—can overlap, making it difficult to differentiate between the various types. As part of the diagnostic process, your doctor will look for very specific signs, symptoms, and disease characteristics. Your doctor will also consider your medical history, physical examination, blood tests, and imaging studies as he rules out some diseases and conditions—and ultimately rules in the final diagnosis.

An accurate diagnosis is necessary so that an appropriate treatment plan can be formulated. Getting it right is essential. 

Medical History and Clinical Symptoms

Your medical history consolidates information about past medical conditions and your current medical condition. To obtain your medical history, you will likely be asked to fill out a written questionnaire at your first appointment, if not in advance of the appointment.

You should be ready to provide your medical history by organizing in advance the following information: your current medication list, a list of allergies, a list of all medical conditions which are currently being treated, medical conditions you were treated for in the past, the name of your primary doctor and other specialists, along with their contact information.

If you keep a symptom diary, it will be easier to re-create your medical history and to keep track of pertinent facts about your condition and changes as they occur.

With the diary, you are more inclined to give your doctor a good overall picture of the symptoms you are experiencing. If you don't have a symptom diary, it is never too late to start. Going forward, it will help with continuity of care. Don't rely on your memory to track details, especially when it is typical for several months to go by between doctor appointments.

Physical Examination

At your initial consultation, your doctor will perform a physical examination to observe any visible signs and symptoms that point to arthritis. Your doctor will check for:

Laboratory Tests

After the medical history and physical examination have been completed, your doctor will likely need more information. Blood tests can provide more specific information and often serve to confirm what the doctor suspects is the diagnosis. Blood tests are also used to monitor disease activity and treatment effectiveness after a diagnosis has been established. On your initial visit, your doctor will most likely order a few of these tests, based on your medical history and examination.

  • Rheumatoid Factor - Rheumatoid factor is an antibody or immunoglobulin which is present in about 70 to 80 percent of adults who have rheumatoid arthritis.
    • Erythrocyte Sedimentation Rate - The erythrocyte sedimentation rate (ESR), also known as sedimentation rate or sedrate, is an indicator of the presence of nonspecific inflammation. Nonspecific inflammation means that inflammation exists somewhere in the body, but the test does not identify the cause.
    • C-reactive Protein (CRP) - C-reactive protein is a protein that is produced by the liver following tissue injury. Plasma levels of CRP increase quickly following periods of acute inflammation or infection, making this test a more accurate indicator of disease activity than the sedimentation rate which changes more gradually.
    • Anti-Cyclic Citrullinated Peptide Antibody Test (anti-CCP) - Anti-CCP is a blood test which is now commonly ordered if rheumatoid arthritis is suspected. A moderate to high level of anti-CCP in blood essentially confirms the diagnosis in a person who has clinical signs of rheumatoid arthritis. The anti-CCP test is more specific than the test for rheumatoid factor. In clinical practice, both the rheumatoid factor test and anti-CCP test should be ordered together.
    • Complete Blood Count - The complete blood count determines the WBC (white blood cell count), RBC (red blood cell count), hemoglobin, hematocrit, several red blood cell indices, and the platelet count. Elevated white blood cell counts suggest the possibility of an active infection. Patients taking corticosteroids may have an elevated WBC due to the medication. Chronic inflammation can cause a low red blood cell count. Low hemoglobin and hematocrit may be indicative of anemia associated with chronic diseases or possible bleeding caused by medications. The platelet count is often high in rheumatoid arthritis patients, while some potent arthritis medications can cause platelets to be low.
    • HLA Tissue Typing - Human Leukocyte Antigens (HLA) are proteins on the surface of cells. Specific HLA proteins are genetic markers for some of the rheumatic diseases. Testing can determine if certain genetic makers are present. HLA-B27 has been associated with ankylosing spondylitis and other spondyloarthropathies. Rheumatoid arthritis is associated with HLA-DR4.
    • Uric Acid - High levels of uric acid in the blood (known as hyperuricemia) can cause crystals to form which are deposited in the joints and tissues. Deposition of uric acid crystals can cause painful gout attacks. Uric acid is the final product of purine metabolism in humans.

    For certain types of systemic rheumatic diseases, biopsies of certain organs can provide important diagnostic information. Also, joint fluid analysis can provide a doctor with many details about the health of a person's joint.

    Medical Imaging

    Imaging studies are also used to help formulate a diagnosis. Your doctor may order x-rays (radiographs), which provide images of your bones and joints. X-rays can reveal deformities and abnormalities of bones and joints. X-rays do not show cartilage, muscles, and ligaments, however.

    MRIs, or Magnetic Resonance Imaging scans, produce cross-sectional images of your body by using a magnetic field and radio waves. Precise information about bones, joints, and soft tissue is provided by MRI images. Very small changes in the body can be detected using MRI.

    A Word From Verywell

    A single symptom or a single test result is not enough to diagnose a specific type of arthritis or rheumatic disease. Certain symptom patterns and tests are combined to rule out certain diseases and rule in a definitive diagnosis. It can seem like an arduous process when you want quick answers. Your patience is needed as your doctor puts the puzzle pieces together.

    Making it even more complicated is the possibility of having more than one rheumatic disease concurrently. Consider this list of 11 rheumatic diseases that mimic rheumatoid arthritis as an example of the complexities associated with diagnosing arthritis. Do you have one rheumatic disease? Do you have more than one rheumatic disease? Do you have overlapping symptoms that complicate the diagnosis?

    Without a doubt, as you go through the diagnostic process, you will have unfamiliar medical terminology tossed in your direction. At Verywell, we are committed to helping you understand the terminology and also the steps along the path to your definitive diagnosis. Even then, the diagnosis is really just the starting point of learning to manage your disease. We offer information on those next steps too, such as understanding your type of arthritis, understanding your arthritis treatment options, managing arthritis pain, improving your quality of life, and more.

    Sources:

    Arthritis Diagnosis. Health Encyclopedia. University of Rochester Medical Center. Reviewed by Hanrahan and Horowitz.

    Arthritis Diagnosis. Arthritis Foundation.

    Kelley's Textbook of Rheumatology. Ninth edition. Elsevier.

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