To diagnose TB you need to test your sputum sample and also a chest x ray is required. TB is of 2 types . Pulmonary and non pulmonary . In pulmonary TB you definitely get cough and fever. In non pulmonary you may or may not. We are all exposed to so many microorganisms . It is when our immune system gets weak we get an infection . We are all immunised for TB at birth as we receive BCG vaccination at birth . It is at this time when our immune system fails to fight against the infection we get symptoms . Our immune system gets compromised in old age ,HIV ,Cancer etc