Coughing occurs when the nerve endings in your airways become irritated. Certain irritants and allergens, medical conditions, and medicines can irritate these nerve endings.
An irritant is something you're sensitive to. For example, smoking or inhaling secondhand smoke can irritate your lungs. Smoking also can lead to medical conditions that can cause a cough. Other irritants include air pollution, paint fumes, or scented products like perfumes or air fresheners.
An allergen is something you're allergic to, such as dust, animal dander, mold, or pollens from trees, grasses, and flowers.
Coughing helps clear your airways of irritants and allergens. This helps prevent infections.
Many medical conditions can cause acute, subacute, or chronic cough.
Common causes of an acute cough are a common cold or other upper respiratory infections. Examples of other upper respiratory infections include the flu, pneumonia, and whooping cough. An acute cough lasts less than 3 weeks.
A lingering cough that remains after a cold or other respiratory infection is gone often is called a subacute cough. A subacute cough lasts 3 to 8 weeks.
Common causes of a chronic cough are upper airway cough syndrome (UACS), asthma, and gastroesophageal reflux disease (GERD). A chronic cough lasts more than 8 weeks.
"UACS" is a term used to describe conditions that inflame the upper airways and cause a cough. Examples include sinus infections and allergies. These conditions can cause mucus (a slimy substance) to run down your throat from the back of your nose. This is called postnasal drip.
Asthma is a long-term lung disease that inflames and narrows the airways. GERD is a condition in which acid from your stomach backs up into your throat.
Other conditions that can cause a chronic cough include:
Certain medicines can cause a chronic cough. Examples of these medicines are ACE inhibitors and beta blockers. ACE inhibitors are used to treat high blood pressure (HBP). Beta blockers are used to treat HBP, migraine headaches, and glaucoma.
Clinical trials are research studies that explore whether a medical strategy, treatment, or device is safe and effective for humans. To find clinical trials that are currently underway for Cough, visit www.clinicaltrials.gov.
The NHLBI updates Health Topics articles on a biennial cycle based on a thorough review of research findings and new literature. The articles also are updated as needed if important new research is published. The date on each Health Topics article reflects when the content was originally posted or last revised.