Final answer:
A cough that is worse at night but not as bad during the day can indicate postnasal drip or sinusitis, chronic bronchial irritation from smoking, pneumonia, or exposure to irritants at work.
Step-by-step explanation:
A patient complaining of a cough that is worse at night but not as bad during the day may indicate several possible conditions. One possibility is postnasal drip or sinusitis, where mucus produced in the sinuses drips down the throat and causes coughing, which can worsen at night. Another possibility is chronic bronchial irritation from smoking, which can cause a cough that is worse in the morning and at night. Pneumonia, an infection in the lungs, can also cause a cough that may be worse at night. Finally, exposure to irritants at work can lead to coughing, especially if the cough is aggravated by certain activities or environments.