It may be something you’d never expect…

The occasional cough is nothing more than your body’s normal lung maintenance—a quick spasm that expels mucus or other irritants from the airways.

On the other hand, a cough that sounds unusual or is unpredictable (for example, there’s no identifiable trigger or the cough occurs at different times of day)…severe…or long-lasting suggests that something else is going on—but what?

Surprising finding: A new study published in Annals of Family Medicine found that a cough from a cold or the flu sticks around longer—for about 18 days, on average—than the one-week threshold that most people consider normal.*

But a cough’s duration is not the only clue to its cause. While it’s not surprising that infections such as pneumonia or whooping cough would lead to coughing, there are other conditions that most people wouldn’t expect. For example…

Asthma. People with asthma assume that they’ll have moments of wheezing or breathlessness. But for some patients, a persistent cough is the only symptom.

What to watch out for: A wheezy-sounding cough that is usually worse at night. Frequent wheezing and/or coughing means that inflamed airways have narrowed, and it’s a hallmark of poorly controlled asthma. Your doctor might recommend spirometry (a simple test that measures your lung capacity) or other lung tests to assess how well—or how poorly—you’re doing.

My advice: If you have a wheezy cough but have never been diagnosed with asthma, see your doctor. If you know that you have asthma and find that you’re using a “rescue” inhaler—a fast-acting bronchodilator that quickly relieves coughing and other symptoms—more than twice a week, see your doctor. You probably need to work harder to reduce flare-ups. This may include adjusting medication, avoiding pollen and air pollution, reducing stress and other measures.

Gastroesophageal reflux disease (GERD). Most GERD patients suffer from both heartburn and coughs, but about one-third experience only a cough or unexplained sore throats. A GERD-related cough occurs when a surge of stomach acid reaches the voice box (the larynx). The irritation and inflammation that result from the acid can lead to a persistent, raspy cough.

What to watch out for: The cough sounds “barky” rather than wheezy. It gets worse when you lie down…after heavy meals…and/or when you consume certain trigger foods or drinks, such as spicy dishes, alcohol, chocolate, onions or citrus. You might also notice that your voice is more hoarse than it used to be.

My advice: For relief, take an over-the-counter (OTC) acid-suppressing drug such as omeprazole (Prilosec) or ranitidine (Zantac). Such a drug is unlikely to cause side effects and often is effective—although it might require long-term use (eight to 12 weeks) before your symptoms improve, so you should be monitored by a doctor.

Also important: Medication usually doesn’t work unless you also make lifestyle changes. For example, don’t eat large meals late at night. In fact, you should avoid food altogether for at least three hours before going to bed. Propping up your upper body with pillows also can prevent stomach acid from going upstream while you sleep.

Postnasal drip. When there’s a persistent drip of mucus from the sinuses, you’re going to periodically cough. Typically, allergies are to blame. People with hay fever often have congestion and postnasal drip. The mucus can irritate the throat as well as the larynx and cause a nagging cough.

What to watch out for: A seasonal cough. If you mainly cough during the spring, summer and/or fall, an allergy-related cough is likely. This cough could sound barky and will probably get worse at night due to mucous drainage. It might be accompanied by other allergy symptoms such as a tickling in the throat, itchy eyes, sneezing, etc.

My advice: Reduce drainage by taking a daily OTC nonsedating antihistamine such as loratadine (Claritin) or cetirizine (Zyrtec).

Nasal steroid sprays are another effective alternative. They start working within hours, although it may take several days—or even weeks—to get the full benefit. Some brands (such as Flonase) are available in OTC versions.

ACE inhibitor drugs. Patients who take these blood pressure–lowering drugs—such as lisinopril (Zestril), captopril (Capoten) and enalapril (Vasotec)—are told that they may experience occasional dizziness. They aren’t always warned, however, about the nasty cough that can result in up to 20% of patients taking them.

What to watch out for: A throat tickle followed by a nagging, dry cough that begins anywhere from a few weeks to a year after starting the medication.

My advice: You can keep taking the drug if the cough isn’t bothering you (and you’re successfully managing your blood pressure). Switching to a different ACE inhibitor may help if you have a mild cough. Patients with severe coughs from ACE inhibitors are often advised to switch to a different drug class altogether—usually an angiotensin-receptor blocker (ARB) such as losartan (Cozaar) or valsartan (Diovan). They work like ACE inhibitors but without the cough.

When a Cough Is COPD or Cancer…

A chronic cough (persistent or episodic) may be the first symptom of two of the most serious lung conditions—lung cancer and chronic obstructive pulmonary disease (COPD), a lung disease that includes emphysema and chronic bronchitis. Both diseases are more common in people who smoke, once smoked or have had significant secondhand smoke exposure than in nonsmokers.  

Important: Even though people who have never smoked are less likely than smokers to get COPD or lung cancer, it can still happen. Don’t take chances. Anyone who has a cough for more than three to four weeks should see a doctor. And call your doctor anytime you cough up blood.

*Note: Be sure to see your doctor if a cough lasts for more than three to four weeks.