The illness is tuberculosis, not cough.

Coughing, like other reflexes like sneezing or blinking, aids in safeguarding the body by allowing the body to rid the respiratory system of mucus or foreign irritants. Coughing is therefore more often a symptom of a sickness than a disease itself, and it can sometimes be a simple bodily protective reflex.
Even without treatment, the majority of coughs go away within a few days, but if they persist for longer than two to three weeks, it is frequently an indication of a more serious issue. For instance, in tuberculosis, the subject of this article, a cough that lasts longer than two to three weeks is frequently the first sign of an active infection.
Potentially dangerous infectious disease tuberculosis primarily affects the lungs. Mycobacterium tuberculosis, the bacterium that causes it, spreads to uninfected people when an infected person coughs, sneezes, laughs, or simply chats, releasing microscopic droplets into the air. The person who was previously uninfected can subsequently breathe in the TB bacteria and these droplets.

The cough associated with tuberculosis frequently begins as a dry, annoying cough that gets worse as it lasts longer than three weeks, producing an abundance of sputum, some of which may occasionally be stained with blood. Fever, sweats, poor appetite, lethargy, weight loss, chest pains, dyspnea, and symptoms specific to the body organ afflicted by TB are additional general signs of tuberculosis. Due to the fact that TB can spread from the lungs to almost any organ of the body.
However, when treating TB patients, cough is particularly important. This is due to the fact that, in the majority of patients, the TB cough and other presenting symptoms may go away as soon as two weeks after beginning therapy, despite the fact that the current standard is that TB treatment should go for six months to assure TB cure. As a result, it becomes challenging to convince TB patients to adhere to their treatment regimen once their presenting symptoms have subsided.
This is due to the fact that once the symptoms that first prompted patients to seek medical attention have subsided, the majority of them lose interest in continuing to take the recommended TB drugs. Although they almost have no possibility of spreading the illness after two weeks of taking the medication, if they don't finish their therapy and recover, they endanger more people. However, using the drugs continuously for 6 months is the best approach to guarantee that the TB bacteria are destroyed. There is a considerable risk that the TB may develop resistance to the TB medications and frequently other antibiotics as well if the treatment is terminated or dose(s) are skipped before the conclusion of the advised six months of treatment.

In addition to killing the patient, TB disease can harm the lungs and result in lung collapse if it is neglected or improperly managed. The other organs of the body that TB affects may also suffer harm. Therefore, it is not unusual to encounter TB causing meningitis, joint degeneration, spinal discomfort, or other health issues. It is advised that people receiving TB therapy never mistakenly believe that their disease has been cured when their cough, which is typically the first symptom, stops.