What Is Chronic Cough?
There are several reasons why a cough may stay with you. The explanation could be as simple as allergies or a lingering infection, but it could also be more serious. It’s important to get to the bottom of the cause and take steps to keep your condition from getting worse.
If you have a cough that's lasted 8 weeks or longer, chances are you have what's known as a “chronic cough.” That means that your cough is likely not caused by a simple respiratory infection or cold, so trying to ignore it won’t make it go away.
More than a nuisance, a chronic cough is an actual medical diagnosis that needs attention. You should see a doctor to determine what's causing it and how to treat it.
Causes and Treatments
The causes of a chronic cough can range from things that are easily treatable to some that are far more serious. Your treatment will depend on the underlying cause. Possible causes include:
Also called upper airway cough syndrome, postnasal drip is a common cause of a long-lasting cough. Allergies, viruses, dust, chemicals, or inflammation can irritate your nasal membranes and trigger runny mucus that drips out of your nose and down your throat. This makes you cough, especially at night when you lie down.
A cough related to postnasal drip may improve when you use a decongestant, nasal or oral antihistamine, nasal glucocorticoid, or nasal spray. The best treatment (or combination of treatments) depends on your symptoms and medical history.
When you have asthma, the muscles around your airways tighten, the lining of your airways swell, and the cells in your airways produce thick mucus. An asthma cough is your body’s way of trying to get air into those restricted areas. Asthma can be triggered by weather, allergies, infections, tobacco smoke, medications, and even exercise and emotions.
If this is what’s triggering your cough, your doctor will probably give you the standard treatment for asthma, which includes an inhaled glucocorticoid to decrease inflammation in the airways. If you also have wheezing or shortness of breath, they may prescribe an inhaled bronchodilator to open up your airways.
Infections
Even after you seem to have recovered from a cold, flu, COVID-19 infection, or pneumonia, the cough may linger. Pertussis, or whooping cough, is a respiratory tract infection and can be an under-the-radar cause of chronic cough. While it's usually covered in childhood immunizations, the CDC recommends that adults get a pertussis booster shot. Your doctor can measure your immunity with a blood test.
Many infections simply need to run their course. It takes time for your lungs to heal and create new cough receptors (which are responsible for triggering the cough reflex). But in some cases, your doctor may prescribe an antibiotic.
Gastroesophageal reflux disease (GERD)
With GERD, a weak band of muscle around the lower part of your esophagus lets stomach acid move into your esophagus instead of sending it to your stomach. The acidic fumes coming from your stomach can irritate your lungs, triggering a chronic cough. Heartburn and chest pain are common symptoms of GERD, though you may not have any symptoms besides the cough.
You may have to make some lifestyle changes to get relief. These include avoiding substances that increase reflux, such as high-fat foods, chocolate, colas, red wine, acidic juices, and too much alcohol. Your doctor may ask you to lose weight or stop smoking. They may prescribe a medication to slow the production of acid in your stomach, called a proton pump inhibitor. It may take several weeks of treatment before you see results. If your cough doesn't improve during this time, you might need further testing.
Blood pressure drugs
Angiotensin converting enzyme (ACE) inhibitors, which are often used to treat high blood pressure, may cause a chronic dry, hacking cough in up to 20% of people who use them. A slight change in medication can take care of this side effect.
Smoking
Smoking damages your lungs (and the rest of your body). Your lungs make mucus to try to get rid of chemicals and particles in tobacco smoke that irritate them. This is what's often referred to as the “smoker’s cough.” It can also be among the first signs of a much bigger problem, such as chronic obstructive pulmonary disease (COPD).
You should stop smoking, but don't expect the cough to clear up right away or at all. Years of smoking mean your lungs will take time to try to repair themselves.
Chronic obstructive pulmonary disease (COPD)
COPD is a group of diseases, including emphysema, chronic bronchitis, and chronic obstructive asthma, that make it hard to get air in and out of your lungs. In most cases, your body makes too much mucus and coughs to try to clear it out. Another symptom is shortness of breath. Over time, COPD can worsen and become life-threatening. Most people who have COPD are smokers or used to be. But it’s possible to have COPD even if you never smoked.
Your doctor can treat COPD with rescue inhalers and inhaled or oral steroids to help control symptoms and minimize further damage. You might also need oxygen therapy.
Although this shouldn’t be at the top of your list of possible causes, it’s another reason to get your cough checked out. Smoking is by far the top cause of lung cancer, although some people who get lung cancer have never smoked. If you’re a nonsmoker and don’t have a family history of lung cancer, it’s not the likely diagnosis. Your lungs include three parts: tissue, airways, and circulation. Only the airways have cough receptors, so if you have a growth in other parts of your lungs, it may not trigger a cough.
Treatment is determined by the size and location of the cancer. You may need surgery, chemotherapy, radiation therapy, targeted drug therapy, or immunotherapy.
If your doctor can't find the cause of your cough and it persists (called a refractory cough ), they might recommend a cough-suppressing medication. There are both prescription and nonprescription versions. Don't take nonprescription medications for long periods without talking to your doctor.
Diagnosing the Cause of a Chronic Cough
To get to the cause of your cough, your doctor will take your medical history and do a physical examination. They’ll want to know things like:
- When did the cough start?
- Is there something that seems to trigger it?
- Do you cough up any phlegm, mucus, or blood?
- Have you been in close contact with anyone who has similar symptoms or may have had a respiratory infection such as a cold, pneumonia, COVID-19, tuberculosis, or whooping cough?
- Do you smoke or have you in the past?
- Do you have trouble with heartburn or indigestion?
- Do you have any allergies?
- Have you had postnasal drip?
- Have you started taking any new medications recently?
Your doctor will take your vital signs, including your temperature, and listen to your lungs and heart with a stethoscope. Based on your symptoms, they may suggest a trial treatment before doing further tests. If your cough improves, you shouldn’t need more testing.
But if your cough persists, or if your diagnosis isn't clear, you may need further testing. These might include:
- Throat swab. Along cotton swab is used to take a culture and test for infection.
- Blood test. This could help tell if your body is fighting an infection.
- Chest X-ray. Your doctor may request a chest X-ray or even a chest CT scan, especially If you smoke or used to, or if you have other medical conditions that can affect your lungs.
- Lung function tests. Your clinician may try to measure the pattern of airflow into and out of the lungs. This includes conducting a spirometry (you’ll breathe out hard and fast into a small plastic device to measure how well you breathe out air) or a methacholine challenge test (also known as bronchoprovocation test) to evaluate how "reactive" or "responsive" your lungs are.
- Acid reflux testing. Acid in your esophagus may trigger coughing. Also called a pH probe, this test measures the level of acid in the fluid in your esophagus. A test called an upper endoscopy may be done in some cases to look for irritation of the esophagus and to obtain a biopsy of the esophagus.
When to Call Your Doctor
If you have a cough that's lasted 8 weeks or more, see a health care provider. Coughs linked to allergies or even the common cold can last months, but you shouldn't ignore them.
Call sooner if you have other symptoms such as shortness of breath or fever. If you’re coughing up blood, seek help immediately.