A chronic cough is a cough that lasts eight weeks or longer in adults, or four weeks in children.
A chronic cough is more than just an annoyance. A chronic cough can interrupt your sleep and leave you feeling exhausted. Severe cases of chronic cough can cause vomiting, lightheadedness and even rib fractures.
While it can sometimes be difficult to pinpoint the problem that's triggering a chronic cough, the most common causes are tobacco use, postnasal drip, asthma and acid reflux. Fortunately, chronic cough typically disappears once the underlying problem is treated.
A chronic cough can occur with other signs and symptoms, which may include:
- A runny or stuffy nose
- A feeling of liquid running down the back of your throat (postnasal drip)
- Frequent throat clearing and sore throat
- Wheezing and shortness of breath
- Heartburn or a sour taste in your mouth
- In rare cases, coughing up blood
When to see a doctor
See your doctor if you have a cough that lingers for weeks, especially one that brings up sputum or blood, disturbs your sleep, or affects school or work.
An occasional cough is normal — it helps clear irritants and secretions from your lungs and prevents infection.
However, a cough that persists for weeks is usually the result of a medical problem. In many cases, more than one cause is involved.
The following causes, alone or in combination, are responsible for the majority of cases of chronic cough:
- Postnasal drip. When your nose or sinuses produce extra mucus, it can drip down the back of your throat and trigger your cough reflex. This condition is also called upper airway cough syndrome (UACS).
- Asthma. An asthma-related cough may come and go with the seasons, appear after an upper respiratory tract infection, or become worse when you're exposed to cold air or certain chemicals or fragrances. In one type of asthma (cough-variant asthma), a cough is the main symptom.
- Gastroesophageal reflux disease (GERD). In this common condition, stomach acid flows back into the tube that connects your stomach and throat (esophagus). The constant irritation can lead to chronic coughing. The coughing, in turn, worsens GERD — a vicious cycle.
- Infections. A cough can linger long after other symptoms of pneumonia, flu, a cold or other infection of the upper respiratory tract have gone away. A common but under-recognized cause of a chronic cough in adults is pertussis, also known as whooping cough.
- Blood pressure drugs. Angiotensin-converting enzyme (ACE) inhibitors, which are commonly prescribed for high blood pressure and heart failure, are known to cause chronic cough in some people.
- Chronic bronchitis. This long-standing inflammation of your major airways (bronchial tubes) can cause a cough that brings up colored sputum. Most people with chronic bronchitis are current or former smokers. Chronic bronchitis is usually part of the spectrum of smoking-related lung disease called chronic obstructive pulmonary disease (COPD). Emphysema is also incorporated under this term, and chronic bronchitis and emphysema often coexist in current or former smokers with COPD.
Less commonly, chronic cough may be caused by:
- Aspiration (food in adults; foreign bodies in children)
- Bronchiectasis (damaged airways)
- Cystic fibrosis
- Laryngopharyngeal reflux (stomach acid flows up into the throat)
- Lung cancer
- Nonasthmatic eosinophilic bronchitis (airway inflammation not caused by asthma)
- Sarcoidosis (collections of inflammatory cells in different parts of your body, most commonly the lungs)
Being a current or former smoker is one of the leading risk factors for chronic cough. Frequent exposure to secondhand smoke also can lead to coughing and lung damage.
Women tend to have more-sensitive cough reflexes, so they're more likely to develop a chronic cough than are men.
Having a persistent cough can be exhausting. Coughing can disrupt your sleep and cause a variety of other problems, including:
- Excessive sweating
- Loss of bladder control (urinary incontinence)
- Fractured ribs
- Passing out (syncope)
Your doctor will ask about your medical history and perform a physical exam. Your doctor may also order tests to look for the cause of your chronic cough.
However, many doctors opt to start treatment for one of the common causes of chronic cough rather than ordering expensive tests. If the treatment doesn't work, however, you may undergo testing for less common causes.
- X-rays. Although a routine chest X-ray won't reveal the most common reasons for a cough — postnasal drip, acid reflux or asthma — it may be used to check for lung cancer, pneumonia and other lung diseases. An X-ray of your sinuses may reveal evidence of a sinus infection.
- Computerized tomography (CT) scans. CT scans also may be used to check your lungs for conditions that may produce cough or your sinus cavities for pockets of infection.
Lung function tests
These simple, noninvasive tests are used to diagnose asthma and COPD. They measure how much air your lungs can hold and how fast you can exhale.
Your doctor may request an asthma challenge test, which checks how well you can breathe before and after inhaling the drug methacholine (Provocholine).
If the mucus that you cough up is colored, your doctor may want to test a sample of it for bacteria.
If your doctor isn't able to find an explanation for your cough, special scope tests may be considered to look for possible causes.
These tests use a thin, flexible tube equipped with a light and camera. With a bronchoscope, your doctor can look at your lungs and air passages. A biopsy can also be taken from the inside lining of your airway (mucosa) to look for abnormalities.
With a rhinoscope, your doctor can view your nasal passages to look for upper airway causes of cough.
A chest X-ray and spirometry, at a minimum, are typically ordered to find the cause of a chronic cough in a child.
Determining the cause of chronic cough is crucial to effective treatment. In many cases, more than one underlying condition may be causing your chronic cough.
If you're taking an ACE inhibitor medication, your doctor may switch you to another medicine that doesn't have a cough as a side effect.
Medications used to treat chronic cough may include:
- Antihistamines, glucocorticoids and decongestants. These drugs are standard treatment for allergies and postnasal drip.
- Inhaled asthma drugs. The most effective treatments for asthma-related cough are glucocorticoids and bronchodilators, which reduce inflammation and open up your airways.
- Antibiotics. If a bacterial infection is causing your chronic cough, your doctor may prescribe antibiotics.
- Acid blockers. When lifestyle changes don't take care of acid reflux, you may be treated with medications that block acid production. Some people need surgery to resolve the problem.
- Cough suppressants. If the reason for your cough can't be determined and it's causing serious problems for you, such as keeping you from sleeping, your doctor may prescribe a cough suppressant. However, there's no evidence that over-the-counter cough medicines are effective.
You should never give children under 4 years of age over-the-counter cough and cold products without checking with your child's doctor. These medicines may harm young children.
While you may initially see your family doctor, he or she may refer you to a doctor who specializes in lung disorders (pulmonologist).
What you can do
It's a good idea to write a list that includes:
- Detailed descriptions of your symptoms
- Information about medical problems you've had
- Information about the medical problems of your parents or siblings
- All the medications, including over-the-counter drugs, and dietary supplements you take
- Questions you want to ask the doctor
What to expect from your doctor
A thorough medical history and physical exam can provide important clues about a chronic cough. Your doctor may ask some of the following questions:
- What are your symptoms and when did they begin?
- Did you recently have the flu or a cold?
- Do you now or have you ever smoked tobacco?
- Does anyone in your family or workplace smoke?
- Are you exposed to dust or chemicals at home or at work?
- Do you have heartburn?
- Do you cough up anything? If so, what does it look like?
- Do you take blood pressure medicine? If so, what type do you take?
- When does your cough occur?
- Does anything relieve your cough? What treatments have you tried?
- Do you get more short of breath with exertion? Or on exposure to cold air?
- What is your travel history?
Follow the plan your doctor gives you for treating the cause of your cough. In the meantime, you can also try these tips to ease your cough:
- Drink fluids. Liquid helps thin the mucus in your throat. Warm liquids, such as broth, tea or juice, can soothe your throat.
- Suck on cough drops or hard candies. They may ease a dry cough and soothe an irritated throat.
- Moisturize the air. Use a humidifier or take a steamy shower.
- Avoid tobacco smoke. Smoking or breathing second-hand smoke irritates your lungs and can worsen coughs caused by other factors. If you smoke, talk with your doctor about programs and products that can help you quit.