- OA is the most common type of arthritis.
- Imaging tests are important both for diagnosing OA and assessing its severity.
- Lab tests can be helpful for ruling out other causes of arthritis.
Several types of arthritis exist. They all involve chronic inflammation of one or more joints. The cause of the symptoms determines the type of arthritis.
Osteoarthritis (OA) is the most common type of arthritis. A breakdown of the cartilage that protects the ends of bones where they form a joint causes it. This leads to pain and inflammation.
Rheumatoid arthritis (RA) is another common type of arthritis. It’s an autoimmune disorder. The immune system attacks the joints. This causes inflammation.
Your primary care doctor will likely conduct tests to pinpoint the kind of arthritis you might have. They can also use imaging tests to determine the severity of arthritis.
For most people, a diagnosis of OA begins with a medical history and a physical exam.
Your doctor will also ask questions about when you experience pain as well as how your symptoms are affecting your daily life.
Your doctor will also look for:
- noises when you move your joints
- swelling of the joints
- a loss of range of motion
- tenderness in the joints
- pain during movement
Imaging tests are important both for diagnosing OA and assessing its severity.
An X-ray can’t show cartilage loss directly. However, it can show changes in the spacing between the bones. This is one of the most obvious signs of OA. As cartilage degrades, the bones move closer together.
X-rays can also allow doctors to identify:
- excess fluid in the joint
- bone damage
- bone spurs
Bone spurs are growths at the end of joints. They can irritate surrounding tissues.
X-rays may not show early destructive changes that are better seen with MRI technology. However, doctors often use them to track the progression of OA.
An MRI test allows your doctor to see soft tissue damage. It’s possible to see changes directly not only in bone but also in:
Doctors can diagnose most cases of OA using physical exams and imaging tests. However, lab tests can sometimes be useful for ruling out other causes of joint pain.
Blood and urine tests
Your doctor can’t diagnose OA using blood and urine tests. However, they can use them to rule out other types of arthritis, such as:
- infectious arthritis
- autoimmune arthritis
- inflammatory arthritis
- metabolic arthritis
They can also include other health problems, such as endocrine disorders and autoimmune diseases.
Your doctor can use blood tests to identify:
- white cell counts
- inflammatory markers
- specific antibodies associated with RA
Your doctor can use urine tests can check for levels of uric acid and other markers of inflammation.
Joint fluid analysis
Joint fluid is also called synovial fluid. Your doctor can get it by inserting a needle into the joint space. They can send the fluid to a lab to be examined for markers of inflammation. This type of analysis can also help your doctor identify other causes of joint inflammation, such as infection or gout.