If you’ve been coughing for more than eight weeks, you’re not alone. About 1 in 10 adults in the UK and US deal with a persistent cough that won’t go away. Most of the time, it’s not a cold, flu, or even allergies. It’s something deeper - and often, it’s one of three things: GERD, asthma, or postnasal drip (now called upper airway cough syndrome). The good news? You don’t need endless tests or expensive scans to find out which one it is. A smart, step-by-step approach can get you answers - and relief - in weeks, not years.
What Counts as a Chronic Cough?
A cough that lasts longer than eight weeks is officially called chronic. It’s not just annoying - it can wreck your sleep, make you dizzy, hurt your ribs, or even cause you to leak urine. But here’s the catch: most people assume it’s a lingering infection. It’s not. In fact, only 1-5% of chronic cough cases are caused by bacteria like pertussis (whooping cough). The real culprits are hidden in plain sight - and they don’t always show up on X-rays.
The American College of Chest Physicians laid out the rule in 2006, and it still holds: if you’re not a smoker and you’re not on an ACE inhibitor (like lisinopril or enalapril), then 80-95% of your cough comes from just three sources. That’s why the first step isn’t a CT scan. It’s asking the right questions.
Step One: Rule Out the Red Flags
Before you even think about GERD or asthma, you need to rule out the scary stuff. If your cough comes with any of these, you need urgent evaluation:
- Bloody phlegm (hemoptysis)
- Unexplained weight loss
- Fever that won’t break
- Swelling in your legs or neck
- Clubbing of your fingers (rounded, swollen fingertips)
These aren’t signs of postnasal drip. They could mean lung cancer, tuberculosis, or heart failure. A simple chest X-ray catches most of these. If it’s normal - which it is in 90% of cases - you can move on. No need for a CT scan. The radiation from a single CT equals 74 chest X-rays, and it only finds cancer in about 0.1% of people with normal X-rays and no red flags.
Step Two: Check Your Medications
Did you start a new blood pressure pill in the last six months? If so, that’s probably your cough. ACE inhibitors - drugs like lisinopril, ramipril, and captopril - cause cough in 5-35% of users. It’s not an allergy. It’s a side effect. The cough usually starts within a week to six months after starting the drug. It’s dry, tickly, and worse at night. Stop the pill, and it often clears up in a few days to two weeks. If you’re on one and have a chronic cough, talk to your doctor about switching to an ARB (like losartan or valsartan). They don’t cause cough.
Step Three: The Big Three - GERD, Asthma, Postnasal Drip
Now you’re ready for the core of the workup. These three conditions cause nearly all chronic coughs. But they don’t always act the way you think.
Postnasal Drip (Upper Airway Cough Syndrome)
Most people think of postnasal drip as mucus dripping down the back of the throat. But it’s not just about mucus. It’s about irritation triggering the cough reflex. That’s why the term changed to upper airway cough syndrome - it’s more accurate.
How do you test for it? You don’t need a nasal scope or allergy test. You try treatment. Take a first-generation antihistamine (like chlorpheniramine or diphenhydramine) with a decongestant (pseudoephedrine) for two to three weeks. No nasal spray. No steroid spray. Just the oral combo. If your cough improves by 70-90%, it’s likely UACS.
Response time? Usually 1-2 weeks. If nothing changes after three weeks, move on. Don’t keep taking it. Side effects like drowsiness and dry mouth aren’t worth it if it’s not helping.
Asthma (Cough Variant Asthma)
Most people picture asthma as wheezing and shortness of breath. But in 24-29% of chronic cough cases, cough is the only symptom. That’s called cough variant asthma. No wheeze. No chest tightness. Just a persistent, dry cough - often worse at night, after exercise, or when breathing cold air.
Standard spirometry (lung function test) can be normal in these patients. That’s why a methacholine challenge test is the gold standard. It measures how sensitive your airways are. If your FEV1 drops by 20% or more with a low dose of methacholine, you have airway hyperreactivity - meaning asthma is likely.
Or, you can try a therapeutic trial. Take an inhaled corticosteroid (like fluticasone) for four weeks. If your cough improves by 60-80%, it’s asthma. You don’t need to wait for a challenge test if you’re willing to try treatment. Many doctors skip the test and go straight to the inhaler.
GERD (Gastroesophageal Reflux Disease)
This one’s tricky. Only half the people with GERD-related cough have heartburn. The rest have what’s called silent reflux. The acid doesn’t burn - it irritates the throat and voice box, triggering cough. You might feel a lump in your throat, need to clear your throat constantly, or have a sour taste in your mouth.
Testing for GERD is messy. A 24-hour pH monitor can show reflux, but it’s abnormal in only 50-70% of cough patients. That’s why the standard test is a therapeutic trial. Take a high-dose proton pump inhibitor (PPI) - like omeprazole 40mg or esomeprazole 40mg - twice a day for four to eight weeks. No food two hours before bed. No caffeine, alcohol, or spicy food.
Only 50-75% of people respond. That’s why some experts now say: don’t start PPIs without evidence. But in practice, it’s still the most common first step. If you’re not better after eight weeks, it’s not GERD.
How Do You Know Which One It Is?
Here’s the truth: many people have more than one. A third of patients have both GERD and UACS. Another 20% have asthma and GERD. That’s why the order matters.
Doctors follow a sequence because some conditions respond faster than others:
- Start with UACS - fastest response (1-2 weeks), easiest to test.
- Then asthma - response in 2-4 weeks, needs inhaler trial or lung test.
- Last, GERD - slowest, 4-8 weeks, and least reliable response rate.
If you’ve tried all three and still cough, you’re in the 10-30% with something else - like chronic refractory cough, vocal cord dysfunction, or even aspiration. But that’s rare. Most people find answers in the first three.
What You Can Do Right Now
You don’t need to wait for a specialist. Here’s your action plan:
- Stop any ACE inhibitor if you’re on one. Ask your doctor for a replacement.
- Take a first-gen antihistamine + decongestant for 14 days. Track your cough daily.
- If no improvement, start an inhaled steroid (like fluticasone) twice daily for four weeks.
- If still coughing, try a high-dose PPI (omeprazole 40mg) twice daily for eight weeks.
- Keep a symptom diary: time of day, triggers, severity. It helps your doctor see patterns.
Don’t take antibiotics. Don’t buy over-the-counter cough syrups - they rarely help chronic cough. And don’t assume it’s allergies. Most allergy meds won’t touch UACS or GERD cough.
Why This Works Better Than Scans
CT scans, bronchoscopies, and allergy tests sound impressive. But they’re not the answer. A 2021 survey of 1,200 UK and US doctors found that 78% of family doctors stick to the three-step trial approach. Only 12% order advanced reflux testing. Why? Because it works.
The Hull Airway Reflux Questionnaire (HARQ) is a free tool you can take online. Score over 13? There’s an 80% chance you have laryngopharyngeal reflux. The Hull Cough Questionnaire scores severity - over 15 means your life is being seriously affected. Use these. They’re validated, free, and better than guessing.
And now, new tools are coming. In 2024, the FDA approved gefapixant for chronic cough - a pill that blocks the cough reflex. Another drug, camlipixant, is under review. These won’t fix the cause - but they’ll help when the cause is hard to find.
What’s Next If Nothing Works?
If you’ve tried all three treatments and still cough, you might have chronic refractory cough (CRC). It’s not in your lungs. It’s in your nerves. Your cough reflex is too sensitive. This isn’t rare - it affects 10-20% of chronic cough patients.
At this point, see a pulmonologist or cough specialist. They may do cough reflex sensitivity testing. They might recommend speech therapy, cognitive behavioral therapy, or newer medications like gefapixant. Don’t give up. There are options - but they start with ruling out the big three first.
Final Thought: Be Patient, But Don’t Wait
Chronic cough isn’t a mystery. It’s a puzzle with three main pieces. Most people find their answer in weeks. But you have to be systematic. Skip the scans. Skip the antibiotics. Start with the evidence-based steps.
If you’ve been coughing for months, you’ve earned relief. You don’t need to suffer through another winter. Start the workup. Track your symptoms. Talk to your doctor. And remember - you’re not crazy. You’re just one step away from answers.
