Coughs are valuable weapons in your body's self-defense arsenal.
Their assignment: Quickly expel intruders from your throat and the airways of your lungs when the normal methods of clearing are not adequate. Usually, cilia (tiny, hair-like fibers) that line the bronchial tubes constantly push material out of the lungs and into the throat. If dust, fluid, viruses, bacteria, or even tumors cause irritation or partial blockage in any part of this region, your cough reflex takes explosive action.
A cough may be triggered by a tickle of dust or water that goes down the wrong way. Suddenly, the muscles of your throat and chest contract and expel the invader in a rush of air and mucus at speeds approaching 100 mph.
This reflex actually originates in a special cough center in the brain. Nerve endings that line the body's airways react to obstructions by sending signals to the cough center, which fires back an order to the muscles to cough up the offensive substance.
Coughs are almost always symptoms of a larger problem. Coughs coupled with a runny nose or fever point to a respiratory tract infection or more serious condition. Coughs can result from an allergy, an asthma attack, chronic rhinitis (inflammation of the nose), indigestion or gastroesophageal reflux (GERD), and even side effects of certain medications (especially those for blood pressure).
There are two basic types of coughs--productive and nonproductive. Productive coughs bring up mucus, often generated by a bacterial or viral infection, or anything that causes an inflammatory reaction in the lungs.
A nonproductive cough--caused by an irritated throat--expels little if any mucus. Dry coughs, as they are also sometimes called, are usually chronic and can be caused by asthma, smoking, allergies, or congestive heart failure.
In general, an expectorant cough medicine is used to help thin mucus so it can be cleared more easily from your lungs.
You'll probably want to suppress a dry cough, on the other hand, especially if you're uncomfortable or having trouble sleeping. Unless your cough is caused by asthma--treatable with an inhaler--you'll likely need an antitussive cough medication. Those with codeine are generally most effective. Codeine can be addictive though and cause side effects such as constipation and drowsiness. Talk to your doctor to find out which medication is best for you and your cough symptoms.
Whether you take a cough medicine or not, drink plenty of fluids, especially hot ones, to help loosen mucus and keep the airways moist. That's what folk cough remedies from chicken soup to tea with lemon are based on.
Because a cough expels bacteria and viruses, always cover your mouth with a disposable tissue. Also remember: Treating the cough doesn't treat the problem behind it. If your cough produces blood or persists more than a week, see your doctor.