There are many different types of rheumatic diseases, and the tests for rheumatic diseases are relatively complicated. Some tests require fasting, while others do not. Even if the blood test is taken after eating, it will not have much effect on the results. However, if the patient is unsure of which tests to perform, it is recommended that blood be drawn on an empty stomach if possible. Since rheumatic diseases are classified into many categories, the items of blood tests vary from disease to disease. If you need to test metabolism-related items, such as blood glucose, blood lipids and blood uric acid, you need to do so on an empty stomach. If the test is done after eating, it will affect the results and interfere with the doctor’s judgment. Sometimes drinking water can also affect the results of these tests, so patients need to fast when they have their blood tested for these items. There are also some items that do not affect the results much when the blood is tested after eating, such as checking autoantibodies, including anti-nuclear antibodies, antiphospholipid antibodies, anti-double-stranded DNA antibodies and checking rheumatoid factor, immunoglobulin, blood sedimentation and C-reactive protein, which do not require fasting. If the patient himself is not sure for which disease and which tests to perform, it is recommended to draw blood on an empty stomach in order to avoid repeated visits to the doctor. At the same time, do not drink water before the test, because rheumatic diseases themselves, in addition to the blood test, but also other body fluid examination, such as urine test is best for the morning urine, so it is recommended not to drink water to prevent interference with the test results. You should wear loose clothing on the day of the blood draw. You should not eat too much greasy high-protein food the day before the blood draw and avoid drinking alcohol. Do not stay up late and ensure sufficient sleep.