How long is too long for a cough to last?

In adults, a cough longer than 8 weeks is chronic by the CHEST guideline definition. In children the line is 4 weeks. MedlinePlus advises contacting a provider once a cough passes 10 to 14 days, and sooner for blood, fever, or trouble breathing.

Why does lisinopril make me cough?

Lisinopril is an ACE inhibitor, and that class causes a dry cough in 5% to 35% of people who take it. The cough can start within hours or months of the first dose. It usually fades a few days to several weeks after the drug is stopped. Ask your prescriber about switching to an ARB rather than stopping on your own.

Can acid reflux cause a cough without heartburn?

Yes. Reflux is one of the four main causes of chronic cough, and it can trigger the cough reflex without any burning in the chest. Doctors often try meal timing changes, head-of-bed elevation, and acid-reducing medication as a test when other causes have been ruled out.

Could a cough that will not go away be whooping cough?

It can, at any age. Pertussis begins like a cold for 1 to 2 weeks, then brings violent coughing fits that usually last 1 to 6 weeks and can last up to 10. Vomiting after a fit or a whooping sound on the breath in are clues. Diagnosis needs a nasopharyngeal swab, so mention the possibility at your visit.

What tests will a doctor order for a chronic cough?

The typical first steps are a chest X-ray and spirometry, a breathing test needed to diagnose asthma. Depending on the findings, a CT scan, blood work, a nose or throat swab, or heart tests may follow. Many doctors also try a targeted treatment for the most likely cause and watch the response.

What Causes a Cough That Will Not Go Away?

The short answer: a cough that lasts more than 8 weeks in an adult is a chronic cough, and it almost always has a findable cause. The usual suspects are postnasal drip (upper airway cough syndrome), asthma, acid reflux, an ACE inhibitor blood pressure pill, smoking, or a lingering post-infection cough. Two or more causes are present in 18% to 62% of patients. See a doctor sooner if you cough up blood, lose weight without trying, run a fever, or feel short of breath.

What counts as a chronic cough?

Doctors sort cough by the calendar. The CHEST Expert Cough Panel defines acute cough as less than 3 weeks, subacute cough as 3 to 8 weeks, and chronic cough as more than 8 weeks in adults (CHEST 2018 guideline). The NIH's MedlinePlus uses the same 8-week line. In children the threshold is shorter: a cough is chronic after 4 weeks (American Family Physician 2017).

The 8-week mark matters because most infection-related coughs have burned out by then. A cough still going at week 9 is more likely one of a short list of conditions that need a specific treatment.

What are the most common causes?

Four conditions account for most chronic cough in adults with a normal chest X-ray: upper airway cough syndrome, asthma, gastroesophageal reflux disease (GERD), and nonasthmatic eosinophilic bronchitis (AFP 2017). They often overlap. Chronic cough has two or more causes in 18% to 62% of patients, and three causes in up to 42% (AFP 2011). That overlap is why treating one cause sometimes helps only partway.

Upper airway cough syndrome (formerly postnasal drip). Mucus from the nose or sinuses trickles down the throat and triggers the cough reflex. Allergies and sinusitis with postnasal drip are common drivers (MedlinePlus). Clues: throat clearing, a tickle at the back of the throat, and a cough that is worse lying down.
Asthma and cough-variant asthma. Asthma is found in 24% to 29% of people with chronic cough (AFP 2017). In cough-variant asthma the cough is the only symptom, with no wheeze. Over-the-counter cough medicine rarely helps; prescription inhalers usually do (ACAAI). Clues: cough after exercise, in cold air, or at night.
Acid reflux (GERD). Stomach acid irritates the esophagus and the airway. Reported prevalence in chronic cough studies ranges widely, from 0% to 73% (AFP 2017). Reflux cough can occur without heartburn. Reflux and asthma also feed each other; our sister site covers how acid reflux makes asthma worse.
Nonasthmatic eosinophilic bronchitis. Airway inflammation without the airway narrowing of asthma. It accounts for 10% to 30% of cases referred to specialists (AFP 2017) and responds to inhaled steroids.

Can a blood pressure pill cause a cough?

Yes, and it is the first thing a doctor should ask about. ACE inhibitors (lisinopril, enalapril, ramipril, benazepril, and others ending in "-pril") cause a dry, tickly cough in 5% to 35% of the people who take them. It is more common in women and can begin within hours or as late as months after the first dose (AFP 2017). The FDA label for lisinopril reports cough 2.5% more often than placebo in hypertension trials (DailyMed). Angiotensin receptor blockers (ARBs) cause it far less often (MedlinePlus).

The fix is a switch, not a suppressant. The cough resolves a few days to several weeks after the ACE inhibitor is stopped, so a four-week trial off the drug is usually enough to confirm the cause (AFP 2011). Do not stop a blood pressure medication on your own. Ask the prescriber to change it to an ARB or another class.

What if the cough started with an infection?

A cough that lingers after a cold, flu, or COVID-19 is called postinfectious cough. It resolves on its own but may persist for three or more months (AFP 2011). If it is slowly improving, watchful waiting is reasonable. If it plateaus or worsens, the "post-viral" label may be hiding asthma, reflux, or sinus disease.

Pertussis (whooping cough) deserves a specific mention. It is not just a childhood disease; it causes serious illness in people of all ages, and childhood immunity fades (CDC). It starts like a cold for 1 to 2 weeks, then moves into rapid, violent coughing fits that usually last 1 to 6 weeks but can last up to 10 weeks. Some people vomit after a fit or make a high-pitched "whoop" on the breath in (CDC). Doctors should consider pertussis in any cough lasting longer than two weeks (AFP 2011), and diagnosis needs a nasopharyngeal swab.

When is a cough a sign of lung disease?

Less often than people fear, but this is where the risk sits. Cigarette smoking or secondhand smoke exposure is a direct cause of chronic cough (MedlinePlus). Smoking is also the leading cause of COPD, and chronic bronchitis is defined as a productive cough lasting at least three months in two consecutive years (NHLBI). Chronic bronchitis still accounts for only about 5% of people who come in for evaluation (AFP 2011).

Other causes include bronchiectasis, interstitial lung disease, tuberculosis, heart failure, and lung cancer. A chest X-ray rules out most infectious, inflammatory, and malignant conditions (AFP 2017), which is why it is the first test for a chronic cough in a smoker or in anyone with a red flag.

Which symptoms are red flags?

American Family Physician lists these alarm features that should shorten the wait for evaluation (AFP 2017):

Coughing up blood (hemoptysis), even streaks.
Unexplained weight loss. See our guide to unintentional weight loss.
Fever, or drenching night sweats with the cough. Our post on night sweats covers when that pairing matters.
Shortness of breath out of proportion to activity, or a lot of sputum.
Hoarseness that lasts more than a few weeks.
Recurrent pneumonia.
A 20 pack-year smoking history, or a current smoker older than 45.

MedlinePlus adds two same-day emergencies: trouble breathing, and a swollen face or throat with difficulty swallowing (MedlinePlus). Stridor (a high-pitched sound breathing in) also warrants a prompt call.

When should you see a doctor, and what will they do?

Book a visit if a cough lasts longer than 10 to 14 days, produces blood, or comes with fever (MedlinePlus). Book it this week if any red flag above is present. Do not wait out the full 8 weeks if you smoke or take an ACE inhibitor; those facts change the plan on day one.

Expect the visit to run in a set order. First, a history: medications, smoking, allergies, heartburn, sinus symptoms, and what makes the cough worse. Second, a chest X-ray, and spirometry, which is required to diagnose asthma (AFP 2011). Other tests that may follow include a CT scan, blood tests, a nose or throat swab, and heart tests such as an echocardiogram (MedlinePlus). Third, treatment aimed at the most likely cause, one at a time: an antihistamine-decongestant for upper airway cough syndrome, an inhaled steroid for asthma or eosinophilic bronchitis, or reflux measures for GERD. Throat symptoms, voice change, or sinus disease may be referred to an ENT; a hard-to-explain cough goes to a pulmonologist.

One caveat: even after a full workup, at least 40% of adults with chronic cough have no medical explanation, now called cough hypersensitivity or refractory chronic cough (Chang et al., Frontiers in Pediatrics 2020).

The bottom line

Count the weeks. A cough past 8 weeks is chronic, and the cause is usually postnasal drip, asthma, reflux, an ACE inhibitor, smoking, or a slow post-infection recovery, often in combination. Check your pill bottle for a "-pril" drug first. Then see a doctor for a history, a chest X-ray if indicated, and spirometry. Go sooner for blood, weight loss, fever, or shortness of breath. Our guide to when to see a doctor covers the general thresholds for other symptoms.

Last updated: September 2026. This article is for informational purposes only and does not constitute medical advice. It cannot diagnose the cause of your cough. Seek emergency care for trouble breathing, coughing up more than a small amount of blood, or a swollen face or throat, and do not stop or change a prescribed blood pressure medication without speaking to the prescriber.