Tuberculosis (TB) affects the lungs primarily. It’s transmitted via a bacterium, Mycobacterium tuberculosis, that passes through the air. TB was once a predominant cause of death around the world. During the 20th Century, developments in medications and the isolation of TB patients helped virtually eradicate TB from the Western world. However, the disease does reappear from time to time — most often in patients with compromised immune systems.

1. A persistent Cough

A persistent cough is one of the best-known TB symptoms, but it’s also a symptom that appears with many illnesses. With TB, you typically have a productive cough. That means your cough causes you to spit up phlegm that contains the TB germ. But a lab needs to test the phlegm to see whether it contains the TB germ.