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 annoying. It can interrupt your sleep and leave you feeling very tired. Severe cases of chronic cough can cause vomiting and lightheadedness, and even break a rib.

The most common causes are tobacco use and asthma. Other common causes include fluid that drips from the nose down the back of the throat, called postnasal drip, and the backward flow of stomach acid into the tube that connects the throat to the stomach, called acid reflux. Fortunately, chronic cough usually goes away once the underlying issue is treated.

A chronic cough can occur with other symptoms, including:

• A runny or stuffy nose.
• A feeling of liquid running down the back of your throat, also known as postnasal drip.
• Clearing your throat a lot.
• Sore throat.
• Hoarseness.
• 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 healthcare professional if you have a cough that lasts for weeks, especially one that brings up sputum or blood, disturbs your sleep, or affects school or work.

A cough that happens once in a while is common. It helps clear irritants and mucus from your lungs and prevents infection. But a cough that lasts for weeks is usually due to a health concern. Many times, more than one health concern causes the cough.

Most cases of chronic cough are due to these causes, which can occur alone or together:

• Postnasal drip. When your nose or sinuses produce extra mucus, it can drip down the back of your throat and cause you to cough. This condition also is called upper airway cough syndrome.
• Asthma. An asthma-related cough may come and go with the seasons. It may appear after an upper respiratory tract infection. Or it can get worse when you're exposed to cold air or certain chemicals or fragrances. In one type of asthma known as cough-variant asthma, a cough is the main symptom.
• Gastroesophageal reflux disease. In this common condition, also called GERD, stomach acid flows back into the tube that connects your stomach and throat. This tube is also known as your esophagus. The constant irritation can lead to chronic coughing. Then the coughing can make GERD worse, creating a vicious cycle.
• Infections. A cough can last long after other symptoms of pneumonia, flu, a cold or another infection of the upper respiratory tract have gone away. A common cause of a chronic cough in adults — but one that often isn't recognized — is whooping cough, also known as pertussis. Chronic cough also can occur with fungal infections of the lung, as well as tuberculosis infection, also called TB, or lung infection with nontuberculous mycobacteria, also called NTM. NTM is found in soil, water and dust.
• Chronic obstructive pulmonary disease (COPD). Also called COPD, this is a lifelong inflammatory lung disease that limits airflow from the lungs. COPD 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, also known as alveoli. Most people with COPD are current or former smokers.
• Blood pressure drugs. Angiotensin-converting enzyme inhibitors, also called 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 — when food or other items are swallowed or inhaled and go into the lungs.
• Bronchiectasis — widened and damaged airways that slowly lose the ability to clear out mucus.
• Bronchiolitis — an infection that causes swelling, irritation and buildup of mucus in the small airways of the lung.
• Cystic fibrosis — a genetic disorder that affects the lungs, digestive system and other organs.
• Idiopathic pulmonary fibrosis — gradual damage and scarring of the lungs due to a cause that isn't known.
• Lung cancer — cancer that starts in the lungs, including non-small cell lung cancer and small cell lung cancer.
• Nonasthmatic eosinophilic bronchitis — when airways are inflamed but asthma is not the cause.
• Sarcoidosis — groups of inflamed cells that form lumps or nodules in different parts of the body but most often in the lungs.

Being a current or former smoker is one of the leading risk factors for chronic cough. Exposure to a lot of secondhand smoke also can lead to coughing and lung damage.

Having a cough that doesn't stop can be very tiring. Coughing can cause various concerns, including:

• Sleep disruption.
• Headache.
• Dizziness.
• Vomiting.
• Sweating a lot.
• Unintended bladder loss, also known as urinary incontinence.
• Broken ribs.
• Passing out, also known as syncope.

Children

A chest X-ray and spirometry, at a minimum, are usually ordered to find the cause of a chronic cough in children.

Finding out what's causing a chronic cough is very important to effective treatment. In many cases, more than one underlying condition may be causing your chronic cough.

If you smoke, your healthcare professional likely will talk with you about your readiness to quit and give you advice on how to achieve this goal. If you're taking an ACE inhibitor medicine, your health professional may switch you to another medicine that doesn't have cough as a side effect.

Medicines used to treat chronic cough may include:

• Antihistamines, corticosteroids and decongestants. These medicines are standard treatment for allergies and postnasal drip.
• Inhaled asthma medicines. The most effective treatments for asthma-related cough are corticosteroids and bronchodilators. They reduce inflammation and open up your airways.
• Antibiotics. If a bacterial, fungal or mycobacterial infection is causing your chronic cough, your healthcare professional may prescribe antibiotic medicines for the infection.
• Acid blockers. When lifestyle changes don't take care of acid reflux, you may be treated with medicines that block acid production. Some people need surgery to resolve the problem.

Medicine to reduce coughing

Your healthcare professional works to find the cause of your cough and the best treatment for you. During that time, your healthcare professional also may prescribe a medicine to reduce coughing, called a cough suppressant. Cough suppressants are not recommended for children.

Cough and cold medicines available without a prescription treat the symptoms of coughs and colds — not the underlying disease. Research suggests that these medicines don't work any better than no medicine at all. These medicines are not recommended for children because of potentially serious side effects, including fatal overdoses in children younger than 2 years old.

Don't use over-the-counter cough and cold medicines, except for fever reducers and pain relievers, to treat coughs and colds in children younger than 6 years old. Also, avoid use of these medicines for children younger than 12 years old. Check with your healthcare professional for guidance.

Follow the plan your healthcare professional gives you for treating the cause of your cough. In the meantime, you can 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. 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. If you smoke, talk with your healthcare professional about programs and products that can help you quit.

You may see your family healthcare professional at first. But you may need to see a doctor who specializes in lung disorders. This health professional is known as a 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 medicines, including those available without a prescription, vitamins, herbal preparations and dietary supplements you take.
• Your smoking history.
• Questions you want to ask the healthcare professional.

What to expect from your doctor

Your healthcare professional may ask some of these questions:

• What are your symptoms and when did they begin?
• Did you recently have the flu or a cold?
• Do you smoke tobacco 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 short of breath or wheeze when you move around or when exposed to cold air?
• What is your travel history?

Your healthcare professional will ask more questions based on your responses, symptoms and needs. Preparing for questions will help you make the most of your time.