Primary infection is almost always asymptomatic, but when symptoms occur, they typically are nonspecific and include low-grade fever and fatigue without a prominent cough.

In active pulmonary tuberculosis, even moderate or severe disease, patients may have no symptoms, except “not feeling well,” along with anorexia, fatigue, and weight loss, which develop gradually over several weeks, or they may have more specific symptoms. Cough is most common. At first, it may be minimally productive of yellow or green sputum, usually when awakening in the morning, but cough may become more productive as the disease progresses. Hemoptysis occurs only with cavitary TB (due to granulomatous damage to vessels but sometimes due to fungal growth in a cavity).

The three stages of TB are:

Primary infection.

Latent TB infection.

Active TB disease