Coughing

WHEN TO SEE YOUR DOCTOR

* The cough persists for more than two weeks and doesn't seem to be getting better.

* You're coughing up a lot of discolored phlegm or what appears to be blood.

* You also have chest pain, fever, chills or night sweats.

What Your Symptom Is Telling You

Is that the dog barking its head off at some rabbit out in the yard? Is it the neighborhood automatic weapons expert playing with his new machine gun? Or is it just your husband having another coughing fit?

Virtually anything could be responsible for that big hack attack, which is the lungs' reflexive response to some sort of irritation—much like a tap on the kneecap with a mallet makes the leg bounce. The key to understanding your cough and choosing its cure is what (if anything) comes up with it—whether it's a dry, unproductive cough or a wet, phlegm-producing cough.

Any irritant in the environment can spark a dry cough, according to Anne L. Davis, M.D., associate professor of clinical medicine in the Division of Pulmonary and Critical Care Medicine at New York University Medical Center and assistant to the director of chest service at Bellevue Hospital Center in New York City. "If you have an allergy, a cough can be a major manifestation of it," she says. Smoke, chemicals, noxious fumes, pollen, dust and animal dander all can irritate the lungs' bronchial tubes, prompting a cough as an attempt to get rid of the offender. "If you're sensitive, even moving into a new office or getting a new carpet might make you cough," she says.

Asthma often produces a dry cough instead of the traditional wheeze, according to Richard L. Sheldon, M.D., a pulmonologist and internist at Beaver Medical Clinic in Banning, California. "In fact, asthma is the most common cause of an undiagnosed cough, especially if you're coughing at night," he says.

Postnasal drip and a digestive problem called gastric reflux are two other frequent and relatively harmless sources of coughing, says Sally E. Wenzel, M.D., assistant professor of medicine at the National Jewish Center for Immunology and Respiratory Medicine in Denver. If the drip trips your cough, you'll usually feel it trickling down and tickling your throat. In reflux, a malfunctioning valve separating your stomach from your esophagus allows digesting food and stomach acid to defy gravity and seep up into your throat, giving you a sour taste in your mouth along with the cough.

Bacterial, viral and fungal infections—from a simple cold to bronchitis and pneumonia—inflame the respiratory tract and can trigger a cough, Dr. Sheldon says. All of these illnesses frequently start with an arid, raspy cough and, as the lungs manufacture more mucus, progress to a sputum-filled hack.

Besides possible fever, chest pain, congestion and a general feeling of the blahs, Dr. Sheldon says, you'll know you have an infection if your phlegm is any color other than clear or white.

Don't worry too much if a cough lingers on after the rest of your cold goes away. "That's just some residual congestion in the outer areas of the lungs that you'll get, especially after a viral cold," Dr. Sheldon says. "It doesn't mean you have asthma or anything like that, just some swelling that the lung senses and wants to cough out."

Smoking, of course, is an obvious source of a lingering cough, especially in a longtime smoker. In response to the irritant, the lungs create many more mucus-secreting cells. But you may not notice the extra phlegm. The muck can't get up the throat easily because the smoke paralyzes the hairlike cilia that line the bronchial tubes, Dr. Sheldon explains. That's why smokers often awaken in the morning with a gagging, sputum-laden cough that stops after they've had a couple of butts.

More seriously, a nagging, constant cough could be chronic bronchitis or emphysema, in which the lungs try to cough out trapped air that can't escape through restricted passages, Dr. Sheldon says. People with these conditions also experience shortness of breath and difficulty in breathing.

Most seriously, the cough could be a sign of a tumor or lung cancer. "Lung cancer is now the most common cancer in both men and women," says Dr. Sheldon, "and it presents itself mostly as a cough."

Symptom Relief

You certainly don't have to go to the doctor every time you get a little tickle in the back of your throat, or even if you pick up a little barking bug. "They come and go," Dr. Sheldon says. "You know what it is. You had it a year ago. Your wife had it two weeks ago. It'll resolve itself in a few days."

If it doesn't, see your doctor. And, if you feel sharp pain when you cough—or you cough up what looks like blood—or that hack persists unabated for a couple of weeks, you'd better visit your doctor. In the meantime, though, don't sit by idly, sputtering and spitting like an old jalopy. Try these cough controllers.

Drown that hack. If you have a phlegm-producing cough, you need to thin the phlegm so you can more easily expel it from your lungs. "Probably the best way to liquefy sputum so it comes up easily is to keep yourself well hydrated," Dr. Sheldon says. So drink as much water as you can stand. (You also want to stay well hydrated if you have a dry cough, which will be much more tolerable if it's drenched with drink.)

Go for guaifenesin. Over-the-counter cough syrups containing guaifenesin help to water down thick mucus, according to Dr. Sheldon.

Don't muzzle your bark. You're coughing because your reflexes are attempting to eliminate an irritation, so stifling the hack with cough suppressants will be counterproductive, especially if your lungs are working overtime on the phlegm assembly line. "You usually want to get that stuff out of there," Dr. Sheldon says. "If you turn that mechanism off, that stuff is going to puddle and pool down there."

Silence it for some sleep. If you have an incessant, naggy, noisy cough that's keeping you and everybody else in the house awake at night, you can consider some judicious use of an over-the-counter cough suppressant. "If you have a bad cough and your ribs hurt and you're losing sleep, you can just shut it off for a while with a cough medication," Dr. Sheldon says. With a phlegm-producing hack, "you have to recognize that you'll have some puddling of mucus down there. But you can accept that so you can get some relief."

The best over-the-counter cough suppressants contain dextromethorphan. A prescription syrup most likely will contain codeine. Both tend to make you drowsy.

Soothe it with salt. If you're coughing a lot, your throat probably is sore and scratchy, and that irritation will only make your cough worse. For relief, gargle frequently with salt water, Dr. Wenzel suggests. Just stir ½ teaspoon salt into one cup warm water. Don't swallow, especially if you're on a salt-restricted diet.

Banish the butts. It goes without saying, but it's worth emphasizing: Smoking causes and aggravates any cough you might have. If you can't quit on your own, ask your doctor to recommend a program that can help you quit.

Be a broncho buster. To tackle that lingering hack, ask your doctor for a bronchodilator. "It accelerates the clearing, and the cough will be gone," says Dr. Sheldon.

Get a whiff of water. Dry air will irritate your lungs and make your cough worse, says Dr. Wenzel. Using a humidifier in your home will moisten the air and make it easier going for your respiratory tract. But keep the humidifier clean, she cautions. They tend to grow mold, which, if you're sensitive to it, will aggravate your cough.