Coughing is an important way to keep your throat and airways clear. However, excessive coughing may mean you have an underlying disease or disorder.

Some coughs are dry, while others are considered productive. A productive cough is one that brings up mucus. Mucus is also called phlegm or sputum.

Coughs can be either acute or chronic:

• Acute coughs usually begin suddenly and are often due to a cold, flu, or sinus infection. They usually go away after 3 weeks.
• Subacute coughs last 3 to 8 weeks.
• Chronic coughs last longer than 8 weeks.

Besides recent upper airways infections, such as the common cold and flu, other common causes of coughs include:

• Allergies and asthma
• Lung infections such as pneumonia or acute bronchitis
• Chronic obstructive pulmonary disease (emphysema or chronic bronchitis)
• Sinusitis leading to postnasal drip
• Lung disease such as bronchiectasis, interstitial lung disease, or tumors
• Gastroesophageal reflux disease (GERD)
• Cigarette smoking
• Exposure to secondhand smoke
• Exposure to air pollutants
• ACE inhibitors (medications used to control blood pressure)

If a child has a barking cough, see croup.