Dear Doctor,

I’ve been coughing for over a month now and medication doesn’t seem to help. I sometimes get a fever in the night. What could be behind this? Sarah

Dear Sarah,

If there is cough associated with night fever sometimes, in a tropical climate, it becomes necessary to exclude tuberculosis (TB) of the lungs. TB is caused by a microbe called mycobacterium TB. The infection is spread from one person to another through the germs being brought out from the throat of the person harbouring them while coughing or talking, and inhaled by a person in proximity. Quantity of the microbes inhaled and resistance of the person in proximity determine whether the person will manifest the disease or not. A person may have TB microbes in his body for some time, but in conditions of lowered immunity, they can become active, causing TB. Along with cough and fever, there is often sweating in the night, loss of appetite and loss of weight. Those in close contact with a TB patient are more vulnerable to develop the disease. It is diagnosed by chest X-ray, blood and sputum tests and is treatable.

Another cause of chronic cough is chronic obstructive airways disease (COAD). It occurs commonly in smokers or persons with chronic exposure to dust of any kind or smoke, like mine workers, quarry workers or farmers or women exposed to smoke while cooking. Here, fever can occur if secondary bacterial infection occurs. Diagnosis is established by blood test, X-ray chest and lung function tests. Treatment is by medicines.

Allergy to some substance or substances can manifest as cough. If one is exposed to the offending substance repeatedly, as dust or fumes, cough can recur repeatedly. This condition can be hereditary. If obstruction of the air tubes of the lungs occurs, as in asthma, cough is associated with breathlessness. In case of superadded bacterial infection, fever can also occur. Blood test, X-ray, lung function tests and allergy tests, help to diagnose the condition and identify allergy, causing substances. Treatment is by anti-allergy drugs and drugs to open the blocked airways of lungs.