Holding your breath for 40 seconds cannot rule out tuberculosis, and the length of breath-holding time is only an indirect indicator of lung function, and is not directly related to whether or not you have lung disease.
Breath-holding is also known as breath-holding test. Clinically, the breath-hold test is usually used to initially determine the subject’s lung function. People with normal lung function can hold their breath for more than 30 seconds after taking a deep breath. Holding the breath for more than 30 seconds at a time can only be used as a preliminary judgment of lung function, and has no direct relationship with whether or not you have a lung disease.
Of course, if there are some patients with lung diseases, such as patients with chronic obstructive pulmonary disease, patients with tuberculosis infection and some patients with lung tumors, they may have pulmonary insufficiency, which is manifested by a shortened breath-holding time. Therefore, the possibility of the disease cannot be completely ruled out in people with normal breath-holding time, whereas people with shortened breath-holding time should be alerted to the possibility of lung disease.
Therefore, the diagnosis of TB requires a comprehensive judgment under the guidance of a physician through pathogenetic, serologic, imaging, pulmonary function and pathologic examinations, and should not be based on a single piece of data that leads to an easy conclusion.