Causes
Three conditions account for most chronic cough in nonsmokers with a normal chest X-ray, and many patients have more than one:- Upper airway cough syndrome (postnasal drip): Mucus dripping down the back of the throat from allergies or chronic postnasal drip triggers throat clearing and cough.
- Asthma: Cough-variant asthma may cause coughing as the only symptom, often worse at night, with exercise, or in cold air.
- Acid reflux: GERD and its throat-focused form, laryngopharyngeal reflux, can irritate the airway even without heartburn.
- Other causes: Smoking, ACE-inhibitor blood pressure medications (such as lisinopril), chronic bronchitis, infections that leave a lingering cough, and, less commonly, lung disease or tumors.
Diagnosis
Evaluation begins with a careful history — smoking, medications, heartburn, allergies, and the cough's timing — and a physical exam. A chest X-ray is usually obtained to exclude structural lung disease. Because the common causes do not always announce themselves, doctors often treat the most likely culprit first and use the response as a diagnostic clue. Breathing tests (spirometry) check for asthma, and further testing such as CT imaging or specialist referral is reserved for cough that resists initial therapy or comes with warning signs.Treatment
Treatment targets the underlying cause, and improvement may take several weeks:- For postnasal drip: Nasal steroid sprays such as fluticasone, antihistamines, and saline rinses calm the upper airway.
- For asthma: Inhaled corticosteroids and bronchodilators; montelukast is sometimes added for allergic or cough-variant asthma.
- For reflux: Acid-suppressing medication such as omeprazole, along with weight loss, avoiding late meals, and elevating the head of the bed.
- Medication review: If an ACE inhibitor is the trigger, switching to a different blood pressure medication typically resolves the cough within a few weeks.
- Smoking cessation: Essential — a smoker's cough that changes character warrants evaluation, not reassurance.
What to Expect from Treatment
Because more than one cause is often present, treatment is frequently layered: a nasal spray and an acid reducer together, for example, when both postnasal drip and reflux contribute. Each therapy needs an adequate trial — usually two to eight weeks — before judging whether it worked, so patience and follow-up visits are part of the plan. Keeping a simple diary of cough triggers, timing, and severity helps your doctor see which treatment is moving the needle. When standard causes have been excluded and treated, some people are left with a hypersensitive cough reflex, for which specific reflex-calming therapies and speech-therapy techniques can help.When to Seek Care
See a doctor sooner for a cough with blood, unexplained weight loss, night sweats, hoarseness lasting more than three weeks, shortness of breath, or a history of heavy smoking. These features call for prompt imaging rather than trial-and-error treatment. A cough that has dragged on for months is rarely something you must simply live with. The internal-medicine team at Zimmer Medical Group works through the causes of chronic cough systematically — schedule a visit to start the evaluation.Working Through a Cough That Will Not Stop
The workup for chronic cough is a sequence of treatment trials, and it fails most often because a trial was too short, aimed at the wrong target, or run two at a time so nobody could tell which one worked. Knowing how each step is meant to run makes the sequence much shorter.
Rule out the two quick fixes first
Anyone taking lisinopril or another ACE inhibitor stops it before any other trial, usually in favor of an ARB such as losartan; the cough can take a month to clear and can appear years after the drug was started. Smokers and vapers stop for the duration of the evaluation, because no treatment can be judged while the irritant continues. A chest X-ray is done before trials begin, not after they fail.
Running each trial so it counts
Postnasal drip is treated with a daily steroid spray such as fluticasone plus an older sedating antihistamine, which works better for cough than the newer non-drowsy types; two to three weeks decides it. Cough-variant asthma is checked with spirometry and treated with an inhaled steroid for at least a month before judging, with montelukast added when allergies are prominent; a cough that improves on an inhaled steroid despite normal breathing tests is often eosinophilic bronchitis, which needs no further asthma workup. Reflux is treated with omeprazole for eight to twelve weeks only when heartburn or regurgitation is present; without those symptoms a PPI rarely helps, and our long-term PPI risks article covers why it is then stopped. Our eight-week cough workup article sets out the full sequence.
What the Florida air adds
Red tide aerosols, Saharan dust in summer, wildfire smoke, and mold in an air conditioning system each sustain a cough that improves indoors or out of town; our red tide and indoor air quality articles cover the local triggers. Pollen here runs nearly year-round, so allergies driving postnasal drip do not follow a northern calendar.
Coughs that are something else
A cough after a chest infection can last up to eight weeks and needs no treatment; whooping cough causes prolonged coughing fits in adults and is worth a test when the fits end in gagging or vomiting. A wet daily cough in a smoker or former smoker is assessed for COPD or bronchiectasis, a night cough with breathlessness lying flat for heart failure, and a throat-clearing cough with hoarseness for laryngopharyngeal reflux. Adults who meet the smoking-history criteria for low-dose CT screening have it regardless of the cough's cause.
When every trial has failed
A cough that persists after each cause has been treated properly is usually a hypersensitive cough reflex, and it responds to speech therapy techniques that suppress the urge and, in some people, to a neuromodulator such as gabapentin at the lowest effective dose. Our pulmonary team coordinates the referral. The American Lung Association and MedlinePlus publish patient guidance on chronic cough.
If your cough has lasted more than eight weeks and no one has run the trials in order, schedule a visit.