Checking for rheumatic diseases requires blood tests. Rheumatic diseases include many kinds of diseases, such as rheumatoid arthritis, systemic lupus erythematosus, spondyloarthropathies, and vasculitis. These diseases have different autoantibodies that can only be detected through blood tests. For example, in rheumatoid arthritis, tests are usually positive for rheumatoid factor, anti-CCP antibodies, and anti-keratin antibodies. For SLE patients, positive antinuclear antibodies, positive anti-double-stranded DNA antibodies, and a significant decrease in complement C3 are usually detected. For spondyloarthropathies, blood tests for the gene HLA-B27 are usually needed to help diagnose the disease. In addition to blood tests, in order to clearly diagnose which rheumatic disease, patients should also do some imaging tests according to their symptoms and signs, such as rheumatoid arthritis patients, checking the X-ray of both hands and wrists; systemic lupus erythematosus patients, cardiac ultrasound, chest CT to assess whether there is any cardiac and pulmonary involvement.