Tuberculosis (TB) is an infectious disease which affects the lungs primarily; it is transmitted via a bacterium (Mycobacterium tuberculosis) as it passes through the air from an infected person who coughs or sneezes or even speaks to someone near who breathes in this air. In previous generations, TB was a predominant cause of death around the world. During the twentieth century developments in medications and the isolation of TB sufferers in specialized sanatoriums helped virtually eradicate this disease from the Western world. Now, due mainly to the emergence of antibiotic-resistant strains, there are some signs that TB is reappearing in developed countries, while in the Third World it continues to pose significant health risks. Immunosuppressed individuals particularly, such as patients with HIV are up to 34 percent more likely to contract active TB infection.

1. A persistent cough

A persistent cough is one of the best-known TB symptoms, but it is also one of the more elusive symptoms. Patients with many other types of illnesses also suffer from persistent coughs. Sometimes the cough is blamed on chronic smoking or asthma, delaying the diagnostic. A cough is usually productive and consists of altered sputum, which contains the Mycobacterium tuberculosis. The confirmation of the diagnosis of tuberculosis is based on the visualization of the mycobacterium with a particular staining technique of the sputum smear or its culture. Therefore, if the coughing does not cease after the best part of a month has passed and if the person coughs up a large amount of phlegm, TB diagnosis needs to be investigated.