Currently, there is no specific blood test for diagnosing osteoarthritis, a degenerative joint disease that commonly affects older adults. However, blood tests may be ordered to rule out other conditions with similar symptoms, such as rheumatoid arthritis or gout.

Some of the blood tests that may be ordered for evaluating osteoarthritis include:

1. Complete Blood Count (CBC): This test measures the number of different types of blood cells in the body, including red blood cells, white blood cells, and platelets. Elevated white blood cell counts may indicate inflammation in the body, which can be associated with osteoarthritis.

2. Erythrocyte Sedimentation Rate (ESR) Test: This test measures the rate at which red blood cells settle in a tube. Elevated ESR levels can indicate inflammation in the body, which is common in osteoarthritis.

3. C-reactive Protein (CRP) Test: This test measures the level of a protein called CRP, which is produced by the liver in response to inflammation. Elevated CRP levels can indicate inflammation in the body, which can be associated with osteoarthritis.

4. Rheumatoid Factor (RF) Test: This test measures the presence of antibodies directed against the body’s own tissues. Elevated levels of RF can indicate rheumatoid arthritis, which can present similar symptoms to osteoarthritis.

5. Uric Acid Test: This test measures the level of uric acid in the blood. Elevated levels of uric acid can indicate gout, another condition that can present similar symptoms to osteoarthritis.

It is important to note that while these blood tests can help identify certain conditions with similar symptoms to osteoarthritis, they cannot definitively diagnose osteoarthritis. A diagnosis of osteoarthritis is typically made through a combination of clinical evaluation, medical history, and imaging tests such as X-rays or MRIs.