cough

WHAT IS COUGH?

A cough is a common reflex action that clears the throat of mucus or foreign irritants. Coughing to clear the throat is typically an infrequent action, although a number of conditions can cause more frequent bouts of coughing. In general, a cough that lasts for less than three weeks is an acute cough. 

CAUSES:

• Viruses. Colds and the flu are the most common causes. While annoying, coughs that are “productive” get germy mucus out of your lungs when you're sick. Most will go away in a few days. After a cold, though, some "dry" coughs last weeks or months. That could be because coughing irritates your lungs,
• Allergies and asthma . If you have them, inhaling a trigger like moldcan cause your lungs to overreact. They're trying to cough out what’s bothering them.
• Irritants. Even if you're not allergic, things like cold air, cigarette smoke, or strong perfumes, can set off a hacking spell.
• Postnasal drip . When you're congested, mucus drips down from your nose into your throat, and makes you cough. You can get postnasal dripfrom colds, flu, sinus infections, allergies, and other problems.
• Acid reflux . When you have heartburn, stomach acids back up into your throat, especially at night. They can irritate your windpipe and make you cough.
• Other causes. Many other problems -- lung inflammation, sleep apnea, and drug side effects -- can be triggers. Get coughs that won't go away checked out to make sure you don’t have a separate problem.