A cough caused by the flu typically lasts anywhere from one to three weeks. Most people experience a flu cough that sticks around for about one to two weeks, but in some cases, it can persist up to six to eight weeks. The cough often starts as dry and hacking, then may become more productive as the body clears the infection. Lingering inflammation in the respiratory airways and complications like bronchitis or pneumonia can prolong the cough duration. If the cough worsens or doesn't improve after a few weeks, it is important to consult a healthcare provider as it might indicate a secondary infection or other complications.

Summary of Flu Cough Duration:

• Typical duration: 1 to 3 weeks
• Common duration for most: 1 to 2 weeks
• Possible extended duration: up to 6 to 8 weeks in some cases
• Early cough: dry, hacking
• Later cough: more productive
• Prolonged cough may need medical evaluation

Thus, while the flu itself resolves within about a week, the cough can linger longer as the respiratory tract heals.