A sputum test for tuberculosis showing non-detection generally means that the tuberculosis bacilli are not detected in the sputum specimen or are not detected because the amount of tuberculosis bacilli in the sputum is low. It is recommended that the patient can repeat the sputum test, and then undergo chest CT, tuberculin test, serologic diagnosis, etc. to help make a clear judgment. There are two possibilities that sputum test for tuberculosis shows non-detection, one is that there is no tuberculosis bacilli in the sputum specimen, and the other is that the tuberculosis bacilli are not detected due to the low amount of tuberculosis bacilli in the sputum. It is recommended that the patient may repeat the sputum test and undergo other tests to help in the diagnosis. This can be done by performing imaging tests such as fiberoptic bronchoscopy, chest X-ray or chest CT, or tuberculin test, specific nucleic acid test, and serologic diagnosis. The above tests are used to help determine the further clarification of the diagnosis.