3. Asthma
People associate asthma with its most common symptom, which is also the most dramatic one: the difficulty to breathe as if your chest was closed or pressed from the outside. However, some variations of asthma may have a variety of symptoms, including dry cough. There are cases where people cough as a reflex, an attempt by the body to breathe and clear out the airways; in other cases, the irritation caused by an allergic reaction linked to asthma can trigger the coughing reflex.
There is a type of asthma called cough variant asthma, and its main symptom is a persistent dry cough. Other symptoms of asthma, besides the universally known difficulty to breathe, is a generalized weakness or fatigue. If you have a persistent dry cough caused by asthma, chances are your breathing capacity is actually reduced, but you have become used to it without knowing, so you don’t notice.