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Diseases A–Z

Chronic cough

Types of cough

It is normal to cough occasionally. Coughing with a cold, flu or allergies is normal.

Coughing has a purpose. It is your body’s way of keeping unwanted stuff from getting into your lungs. Coughing helps clear extra mucus from your airways (small tubes in your lungs). This extra mucus could be caused by smoking, a cold, nasal or sinus problems, a lung infection or a lung disease, like asthma or COPD.

A cough may be caused by a condition not related to your lungs, such as heartburn, some medications, or throat irritants (for example, dust, pollution, chemicals in your workplace or home).

Coughing is not normal if you are coughing up blood or thick mucus. If your cough makes you very tired, or light-headed, or causing chest or stomach pain, or causing you to “wet” yourself, you should talk to your doctor to find out the cause.

What are the different types of cough?

Doctors divide coughing into three groups, based on how long the cough has lasted. There are three types: acute (coughing less than 3 weeks), sub-acute (coughing 3-8 weeks), or chronic (coughing longer than 8 weeks).

A cough lasting less than 3 weeks (acute cough)

A cough lasting 3 to 8 weeks (sub-acute cough)

A cough lasting 8 weeks or longer (chronic cough)

A cough lasting less than 3 weeks (acute)

Just about everybody coughs sometimes. From time to time, you may get a cough that lasts a short while (known as an acute cough), and then goes away. A main cause of acute cough is the common cold. You may catch a cold then have a cough that lasts two or three weeks. If you have an acute cough, follow this treatment advice.

Acute cough warning signs — See a doctor or go to the nearest emergency room, if you are:

  • Extremely short of breath
  • Turning blue in the lips or fingernails
  • Swelling in the lips
  • Coughing up blood

Frequently asked questions on cough

A cough that lasts 3-8 weeks (sub-acute cough)

A cough that lasts for 3-8 weeks is often caused by a cold or other lung infection that lasts longer than normal. A cough that lasts 3-8 weeks may go away by itself but it may also need treatment. If you have a three week cough and you are not sure if you should see your doctor, read the following questions:

  • Are you coughing up blood?
  • Are you short of breath?
  • Has your cough has changed over time?
  • Are you losing weight without trying?
  • Are you coughing up phlegm?
  • Do you have a fever?
  • Do you currently smoke?
  • Did you smoke in the past?
  • Are you living with asthma or COPD or other respiratory conditions?

If you answered yes, to any of the following questions, you should talk to your doctor about your cough.

To diagnose your cough your doctor may ask you questions about: your family history, things you may have been exposed to at home or work, and if you smoked. Your doctor may want to examine you. Your doctor may also give you a few tests including:

  • a chest X-ray – A chest X-ray takes a picture of your lungs. This can tell your doctor if you have something like pneumonia or lung cancer.
  • spirometry - This test measures how much air you can breathe out and in. Your doctor will use spirometry to diagnose conditions such as asthma or COPD.

Frequently asked questions on cough

Treatment for cough

How a cough is treated depends on what's causing it. For example, if your cough is caused by asthma, your doctor may give you asthma medicine. If your cough is caused by smoking, your doctor will help you quit.

In general, doctors do not recommend over-the-counter cough medicines. Over-the-counter cough medicines do not treat what’s causing the cough.

Find a lung testing clinic in your area.

A cough lasting 8 weeks or more (chronic cough)

A cough that lasts 8 weeks or longer is known as a chronic cough. A chronic cough is not a disease in itself. It is a sign of something wrong. That's why it's important to see your doctor and find out the cause.

Some of the most common causes of chronic cough include:

  • post-nasal drip syndrome, when mucus drips down your throat from the back of your nose
  • something at home or work that is irritating your nose or airway
  • allergies
  • asthma
  • smoking
  • COPD (new name for emphysema and chronic bronchitis)
  • acid reflux (sometimes called gastro-esophageal reflux disease or GERD)
  • some high blood pressure medications
  • or a combination of these causes

In rare cases, chronic cough can be caused by serious diseases like tuberculosis (TB), lung cancer. Your doctor may want to order a chest x-ray to determine whether you have a serious condition.

Diagnosing a chronic cough

The first step in treating a chronic cough is to find out what's causing it. Your doctor may do several tests to diagnose the cause.

First your doctor will ask about your medical history. He or she might ask you questions such as whether you have allergies, what medications you are currently taking, whether you smoke or smoked in the past, if you use chemicals at home or work, and if you have been sick lately. Before you go to your doctor, write down everything you want to tell him or her. Your doctor should do a physical exam and may also order a chest X-ray.

Your doctor may also order lung function tests (spirometry). Find a lung testing clinic in your area.

Your doctor may refer you to a breathing specialist (a respirologist).

Once the doctor knows the cause of your cough, he or she will recommend a treatment.

Most of the time, you can get effective treatment for your cough. If you see your doctor and get help early on, it will be easier to treat your cough.

Frequently asked questions on cough

Treatment for cough

The treatment for cough depends on what's causing it. For example, if your cough is caused by asthma, the doctor may give you asthma medicine. If your cough is caused by smoking, your doctor will help you quit.

In general, doctors do not recommend over-the-counter cough medicines for acute or chronic coughs.

For coughs in children under 14 years of age: Children under 14 years should not take over-the-counter cough medicines (cough suppressants or expectorants). Cough is very common in children. Cough and cold medicines (including cough syrups) are not useful in children and can actually be harmful. In most cases, a cough will go away on its own. Sometimes coughs are caused by an underlying problem, like asthma or another lung disease, or by something in the air (pollution, smoke, allergens). Doctors will treat the underlying problem.

For adults: Adults with acute cough or upper airway cough syndrome (also called post-nasal drip syndrome) could take an antihistamine with a decongestant. Adults should not take over-the-counter cough expectorants or cough suppressants, including cough syrups and cough drops. They do not treat the underlying cause of the cough.