Dry Cough: Causes and Management

A dry cough is a cough that produces no phlegm or mucus. It often feels like a tickle or irritation at the back of the throat that won't go away. After a cold or respiratory infection, a dry cough can linger for two to three weeks while the airways heal. That's normal.

When a dry cough persists beyond three weeks, or keeps coming back, it usually points to an underlying cause that needs identifying. The three most common culprits in adults are asthma, acid reflux, and post-nasal drip. Less often, medication side effects or more serious respiratory conditions are responsible.

Common causes of a persistent dry cough

Post-viral cough

The most frequent cause. After a cold, flu, or COVID infection, the airways remain inflamed and hypersensitive. This can trigger a dry cough that persists for weeks after the infection itself has cleared. It resolves on its own, though it can be frustrating while it lasts.

Simple measures help: staying hydrated, honey in warm water, and avoiding smoke or strong fumes. If the cough exceeds 8 weeks, NICE recommends further investigation.

Asthma and cough-variant asthma

Asthma doesn't always present with wheezing. Cough-variant asthma causes a dry cough as the main (sometimes only) symptom, often worse at night or after exercise. Cold air and allergens can trigger it.

Diagnosis involves spirometry (a breathing test that measures how well your lungs work) and sometimes a trial of inhaler treatment. If the cough responds to an asthma inhaler, that confirms the diagnosis.

Gastro-oesophageal reflux disease (GORD)

Stomach acid rising into the oesophagus irritates the airway and triggers a cough reflex. You might have classic heartburn alongside the cough, or you might not. Silent reflux, where the cough is the dominant symptom, is easily missed.

Treatment typically involves a trial of proton pump inhibitors (PPIs) for 4 to 8 weeks, along with lifestyle changes: avoiding late-night eating, reducing caffeine and alcohol, and sleeping with the head of the bed slightly raised.

Post-nasal drip

Mucus from the sinuses dripping down the back of the throat causes a tickling sensation and a persistent cough. Common triggers include allergies (hay fever), chronic sinusitis, and changes in weather.

A nasal corticosteroid spray is usually the first treatment. Antihistamines help if allergies are driving it. Saline nasal rinses can also provide relief.

ACE inhibitor medication

Blood pressure medications ending in "-pril" (ramipril, lisinopril, perindopril) cause a dry cough in roughly 10-15% of people who take them. The cough can start weeks or even months after beginning the drug.

If you suspect this is the cause, don't stop the medication yourself. Your GP can switch you to an alternative (usually an ARB such as losartan) and the cough typically clears within one to four weeks.

Other causes

Less common causes include environmental irritants (dust, mould, air pollution), whooping cough (pertussis) in adults who weren't vaccinated or whose immunity has waned, and, rarely, lung conditions including interstitial lung disease or lung cancer.

Smoking is an obvious cause, though smoker's cough is usually productive rather than dry. If you smoke and your cough changes character, that warrants prompt investigation.

Diagnosis

Your GP will ask about the duration, pattern, and triggers of your cough. They'll examine your chest and throat, and may check your oxygen levels.

Depending on what they find, next steps might include a chest X-ray, spirometry, blood tests (to check for infection markers or allergies), or a trial of treatment for suspected reflux or asthma. Most of these can be arranged the same day at our clinic.

A cough that has lasted more than 8 weeks, or one that started suddenly with no obvious cause, should always be investigated. NICE guidelines are clear on this point: prolonged cough needs a diagnosis, not just symptom management.

How we can help

We see patients with persistent coughs regularly. A same-day GP appointment (£150) includes a full clinical assessment, and we can arrange chest X-rays, spirometry, and blood tests on-site if needed.

If your cough turns out to need specialist input, we refer to respiratory consultants directly, usually within 48 hours. No waiting for NHS referral letters.