Is a cough a symptom of a cold or the flu?

Yes, a cough is a common symptom of both the common cold and the flu (influenza). 

Cold: When you have a cold, a cough is often one of the early symptoms. It typically starts as a dry or scratchy throat and may progress to a productive cough with mucus as the cold progresses. Coughing in a cold is often mild to moderate in severity.

Flu (Influenza): Influenza can also cause a cough, and it's one of the hallmark symptoms of the flu. The cough associated with the flu can be dry and hacking, and it may be more severe and persistent than the cough seen in a typical cold.

In both cases, the cough is usually a result of the body's immune response to the infection and its attempt to clear mucus and irritants from the airways. It's important to note that while a cough is a common symptom of colds and the flu, other symptoms such as fever, body aches, congestion, and fatigue are also often present with the flu and may help differentiate it from a common cold. If you're unsure whether you have a cold or the flu, it's advisable to consult a healthcare professional for an accurate diagnosis and appropriate treatment.