Bloodway dissemination is one of the types of tuberculosis. Elderly people infected with tuberculosis bacteria in adolescence, due to the body’s strong resistance to disease at that time, did not cause the onset of disease, to the old age due to the decline in immunity, so that the tuberculosis bacteria in the latent body strength to reproduce and grow and the onset of the disease, most of the resulting onset of the disease. Then, what are the examination items that should be done for hematogenous dissemination? The following is a detailed introduction to the examination items of bloodway dispersal: 1, sputum tuberculosis examination is the most specific method to confirm the diagnosis of tuberculosis. Thick smear antacid staining microscopy is fast and easy, with a high positive rate and few false positives, so it is generally recommended. Positive sputum antacid bacilli provide the initial diagnosis. It is estimated that the minimum concentration of tuberculosis bacilli for sputum smear positivity is 10 bacilli/ml, and 50% to 80% of patients with tuberculosis are sputum smear positive. Cultures of tuberculosis bacilli can be differentiated from other antacid bacilli, except in those who have been treated with chemotherapy, where smear-positive cultures are occasionally negative, and cultures have a higher sensitivity and specificity than smears in untreated tuberculosis. The sensitivity and specificity of culture in untreated TB is higher than that of smear test. Further drug sensitization of cultured strains can provide an important reference for treatment, especially retreatment. Smear-positive (smear-positive) cases chemotherapy within 7-10 days on the laboratory growth of tuberculosis bacilli very little effect, while only a very small amount of excretion of bacilli smear-negative (smear-negative) cases chemotherapy rapidly affects the results of the culture, so it is necessary to leave the specimen before the start of chemotherapy. Early morning gastric fluid sampling for tuberculosis bacilli in young children who have no sputum and do not cough up sputum is still a worthwhile method when necessary. In adults, nebulized sputum or suction sampling via tracheal puncture is also an alternative sampling method. The biggest disadvantage of tuberculosis culture is the slow growth, it takes 4 to 6 weeks to see colonies, if continuous drug sensitivity testing will take 3 to 4 months, and there is also a positive rate is not ideal and difficult to standardize and other problems. Due to the structural abnormality of the enzyme required for DNA synthesis in M. tuberculosis, there has been no breakthrough in the research on rapid culture for a long time. The current application of the Bactec460TB system has solved the problem of rapid detection of M. tuberculosis. This uses Mycobacterium 7H12 medium containing radioactive 14C palmitic acid as a substrate. When the test specimen is inoculated in this medium, if Mycobacterium is present, its metabolites interact with the substrate to produce 14CO2 which is sent to the ionization chamber and the results are automatically displayed. Addition of NAP (P-nitro-acetylamino-β-hydroxypropiophenone) drug can be identified with atypical mycobacteria. The system can also be used to determine the susceptibility to anti-tuberculosis drugs. Most applications have shown that the Bactec system can be used for mycobacterial detection in an average of 9 days, tuberculosis identification in 5 days, and drug susceptibility testing can be completed in 6 days, which is a significant reduction in the detection time, and a very high rate of compliance with conventional methods. The disadvantages are that equipment and reagents are expensive and drug resistance may be underestimated. Elderly people have high misdiagnosis rate of tuberculosis, wide range of lesions, easy to form cavities, so sputum positive rate of tuberculosis can be as high as 85.9%. 2.Knotin test Knotin is the metabolite of tuberculosis bacteria, the main component of tuberculosis protein, prepared from the filtrate of human tuberculosis bacteria grown in liquid culture medium. Old tuberculin (OT) antigen is impure, can cause non-specific reaction. Pure protein derivative (PPD) is superior to OT, and PPD-S made by precipitation with sulfuric acid has been designated by WHO as the international standard nodulin for mammals, while the Danish nodulin commissioned by WHO and designated as PPF-RT-32 (with Tween80 stabilizer) has been widely adopted internationally. However, PPD antigen is still complicated. Intradermal injection method is commonly used for the knotin test. With 0, 1 ml of knotin release solution in the left forearm medial intradermal injection, so that the local skin, 48 ~ 72h to observe and record the results. The corresponding potency and content of 0, 1 ml of different knotin preparations are shown in Table 1.Epidemiological investigations and clinics generally take 5 TU as the standard dose. The results were judged on the basis of the size of the diameter of the local swollen knots in 72h: ≤4mm negative (-), 5-9mm weak positive reaction (+), 10-19mm moderate positive reaction (++), ≥20mm or not more than this diameter but not blistering, necrosis, for strong positive reaction (++++). Short-term repeated test can cause compound strong effect, so the clinical application of direct use of the standard dose, do not advocate starting from a small dose gradually increase, repeat the test. Elderly people due to immunocompromise, tuberculin test positive rate is low and ≥ 70 years of age is even lower only about 10%.