The anti-O test is an antibody produced by the body after infection with group A hemolytic streptococci. The anti-streptococcal hemolysin “O” test has some diagnostic significance for rheumatic fever, but it is not the so-called gold indicator. Rheumatic fever is one of the rheumatic diseases, because its onset is related to the throat infection with group A hemolytic streptococcus, and anti-“O” is elevated in the blood test, so many patients equate the positive anti-“O” in the blood test with rheumatic disease, which is actually not This is not entirely correct. First of all, a positive anti-“O” only indicates that the human body is infected with group A hemolytic streptococcus, while a variety of diseases can cause a positive anti-“O”, such as tonsillitis, pharyngitis, infective endocarditis, nephrotic syndrome, tuberculosis and so on. Secondly, it takes a long time for the anti-O to start to rise and gradually decrease until it returns to normal level. Generally speaking, after 2 weeks after the human A hemolytic streptococcus, the blood appears positive for anti-O, and after about 4 weeks, it can be the highest level, and then slowly declines, and it takes more than 6 weeks to drop to normal level. Therefore, when a blood test reveals a positive anti-“O” level, it is likely that it is already in the decline period and the disease that caused the positive anti-“O” level has recovered itself. In addition, due to the widespread use of antibiotics, the rate of anti-O positivity has gradually decreased. Thus, a positive anti-“O” test is not equivalent to rheumatic fever, nor can it be equated with rheumatic disease. If you have a positive anti-“O” test, don’t be nervous, but go to the rheumatology department for further treatment with the help of a doctor.