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. Chronic cough can also occur with fungal infections of the lung, tuberculosis (TB) infection or lung infection with nontuberculous mycobacterial organisms.
- Chronic obstructive pulmonary disease (COPD). COPD, a chronic inflammatory lung disease that causes obstructed airflow from the lungs, includes chronic bronchitis and emphysema. Chronic bronchitis can cause a cough that brings up colored sputum. Emphysema causes shortness of breath and damages the air sacs in the lungs (alveoli). Most people with COPD are current or former smokers.
- 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.
Less commonly, chronic cough may be caused by:
- Aspiration (food in adults; foreign bodies in children)
- Bronchiectasis (damaged, dilated airways)
- Bronchiolitis (inflammation of the very small airways of the lung)
- 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)
- Idiopathic pulmonary fibrosis (chronic scarring of the lungs due to an unknown cause)
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.
Having a persistent cough can be exhausting. Coughing can cause a variety of problems, including:
- Sleep disruption
- 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. A thorough medical history and physical exam can provide important clues about a chronic cough. 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 chronic cough or your sinus cavities for pockets of infection.
Lung function tests
These simple, noninvasive tests, such as spirometry, 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 may include:
- Bronchoscopy. Using a thin, flexible tube equipped with a light and camera (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.
- Rhinoscopy. Using a fiberoptic scope (rhinoscope), your doctor can view your nasal passageways, sinuses and upper airway.
A chest X-ray and spirometry, at a minimum, are typically ordered to find the cause of a chronic cough in children.
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 are currently smoking, your doctor will discuss with you your readiness to quit and provide assistance to achieve this goal.
If you're taking an ACE inhibitor medication, your doctor may switch you to another medicine that doesn't have cough as a side effect.
Medications used to treat chronic cough may include:
- Antihistamines, corticosteroids and decongestants. These drugs are standard treatment for allergies and postnasal drip.
- Inhaled asthma drugs. The most effective treatments for asthma-related cough are corticosteroids and bronchodilators, which reduce inflammation and open up your airways.
- Antibiotics. If a bacterial, fungal or mycobacterial infection is causing your chronic cough, your doctor may prescribe medications to address the infection.
- 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.
During the time your doctor is determining the reason for your cough and beginning treatment, your doctor may also prescribe a cough suppressant to try to speed your symptom relief.
Over-the-counter cough and cold medicines are intended to treat the symptoms of coughs and colds, not the underlying disease. Research suggests that these medicines haven't been proved to work any better than inactive medicine (placebo). More important, these medications have potentially serious side effects, including fatal overdoses in children younger than 2 years old.
Don't use over-the-counter medicines, except for fever reducers and pain relievers, to treat coughs and colds in children younger than 6 years old. Also, consider avoiding use of these medicines for children younger than 12 years old.
Lifestyle and home remedies
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.
- Consider taking honey. A teaspoon of honey may help loosen a cough. Don't give honey to children younger than 1 year old because honey can contain bacteria harmful to infants.
- Moisturize the air. Use a cool-mist humidifier or take a steamy shower.
- Avoid tobacco smoke. Smoking or breathing secondhand 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.
Preparing for an appointment
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
Before your appointment, make 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, vitamins, herbal preparations and dietary supplements you take
- Your smoking history
- Questions you want to ask the doctor
What to expect from your doctor
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 or wheeze with exertion? Or on exposure to cold air?
- What is your travel history?
Your doctor will ask additional questions based on your responses, symptoms and needs. Preparing and anticipating questions will help you make the most of your time with the doctor.