When should you worry about a cough?

11th January, 2019 • 5 min read

Coughing is your body’s way of clearing your airways of mucus and irritants. Most coughs will resolve without treatment in two to three weeks.

But if your cough lasts longer than three weeks, or you have other worrying symptoms, you should see a doctor.

Coughs can either be dry or productive. A dry cough is often described as a ‘tickly cough’, where no mucus is produced. A productive cough is a cough which produces mucus (phlegm).

A cough that lasts less than three weeks is usually the result of a common virus, like the cold or flu, and is rarely a cause for concern.

Keep reading to find out more about the different causes of coughs, how to treat them, and when to see a doctor.

Common causes of acute coughs

An acute cough is a cough that lasts for less than three weeks but tends to improve after one week.

This type of cough is often the result of a viral infection such as the

. Anyone can be infected by a viral infection, but they are most common in young children between the ages of 5-6.

Other causes of an acute cough include:

  • Upper respiratory tract infections - these are the most common cause. They usually get better within a week without treatment, and symptoms can last up to three weeks
  • Lower respiratory tract infection - these are less common and can be more serious. They can lead to conditions such as
  • Irritants - if you breathe in something like chemical fumes or smoke it can irritate your airways and cause a cough

Common causes of subacute coughs

A subacute cough is a cough that lasts for more than three weeks (acute cough) but less than eight weeks (chronic cough).

There are different causes of a subacute cough, such as:

  • When your airways are still swollen and irritated following an infection. Even though the germs are gone, your cough remains. This is known as airway hyperresponsiveness
  • Whooping cough
    , which causes a persistent dry cough
  • Other infections like

Common causes of chronic coughs

A chronic cough is a cough that lasts for more than eight weeks. This type of cough can result from a number of different conditions, such as:

  • Postnasal drip - when your nose produces too much mucus, which drips down the back of your throat. This can be caused by
    hay fever
    nasal polyps
    , and infections
  • Acid reflux
    - this is when acid from the stomach flows up into the airways
  • Asthma
    - undiagnosed or poorly controlled asthma
  • Medication - certain medications such as angiotensin-converting enzyme (ACE) inhibitor medicines
  • Chronic obstructive pulmonary disease
    (COPD), a lung disease that primarily affects smokers, and can also cause breathlessness
  • Irritants, such as smoke

Less common causes of chronic coughs

  • Foreign bodies - food or other objects that have gone down your windpipe instead of your food pipe can cause you to cough
  • Lung cancer
    - in some cases lung cancer can cause a cough. This is more likely if you are a smoker
  • Cystic fibrosis
    - this is a genetic condition that affects the lungs and causes a chronic cough
  • Pneumothorax - this is when air gets trapped in the chest, outside of the lungs
  • Bronchiectasis
    - this condition causes your airways to widen and produce excess mucus
  • Pulmonary embolism
    - this is a blood clot in your lungs

What to expect from a cough

There are two types of cough, a dry cough, which is a tickly cough in the back of your throat that doesn’t produce any mucus, and a productive cough, which is a chesty cough that does produce mucus.

A dry cough will usually last around 2-3 weeks, and is likely caused by an upper respiratory tract infection.

Most adults will experience an acute cough two to five times a year. It is rarely a cause for concern, and should get better without specific treatment.

However, a chronic cough might suggest an underlying lung condition. You should see a doctor if your cough lasts for longer than three weeks.

Cough treatments

Mild, acute coughs don’t always require treatment, and most will resolve on their own. You should try to rest and drink plenty of fluids, including warm water with lemon and honey.

If your cough is caused by a specific illness, then you will need to treat the condition to resolve the cough.

When to see a doctor

Most coughs only last a few days to a few weeks and they are usually caused by a common virus. However, you should see a doctor about your cough if:

  • You have had it for more than three weeks
  • Your cough is very bad or is getting worse
  • You have chest pain
  • You’re also experiencing unexpected weight loss
  • You have swollen glands
  • You are struggling to breathe
  • You have a weakened immune system

If you are coughing up blood you should see a doctor immediately.


Coughs can linger, but usually there’s nothing to worry about.

Remember, if your cough is caused by a virus, then antibiotics won’t help. Instead, stay hydrated, and get plenty of rest and relaxation.

If your cough lasts longer than three weeks you should see a doctor. You should also see a doctor if you experience any other worrying symptoms.

Important: Our website provides useful information but is not a substitute for medical advice. You should always seek the advice of your doctor when making decisions about your health.