Coughing is an automatic reaction to try to clear your airways. The airway may be partially blocked by mucus, smoke, chemicals that you breathe in or a foreign body. Everyone will cough occasionally to “clear their throat”. But it is important to seek medical attention if you have a cough that lasts for more than three weeks. If you’re short of breath, cough up blood or have unexplained problems like weight loss or a fever, you should see your GP urgently. The most common causes are mentioned below.
What is a cough?
A cough is when you have an automatic (reflex) muscle action that forces air up and out of your lower airways (lungs) and upper airways (windpipe, nose and mouth). You may cough to 'clear your throat' if you choke on food and it enters your windpipe instead of going down the food pipe (oesophagus). Or you may need to cough if you breathe in chemicals or smoke that irritate your airways. Doctors call a cough 'short-term' (acute) if it lasts for less than three weeks and 'long-term' (chronic) if it lasts for longer than three weeks.
Who is affected by cough?
Cough affects us all if we need to clear our airways. Acute cough usually improves after one week. The most common cause is a viral infection which causes a runny nose and cough. Viral infections can affect anyone, but young children commonly have 5-6 viral infections a year, especially in the winter months.
Chronic cough affects around 10% of all adults. The most common causes in adults who are otherwise well are as follows:
What investigations will be advised?
The doctor will want to know how long your cough has lasted and whether you have any other symptoms. The doctor will particularly ask about symptoms which may suggest an underlying serious condition ('red flags').
Red flag symptoms that may suggest serious underlying disease:
Your doctor will want to know:
These details will help the doctor to make a diagnosis. Your doctor will examine you. He or she will check your throat, lungs and heart. You may be asked to have lung function tests including a peak flow reading. You may be sent for a chest X-ray. Further tests of your lungs may be necessary.
What causes cough?
Acute cough can be due to one of the following causes - the most common being a viral infection:
Chronic cough is usually due to one of the following causes:
What treatments may be offered?
Treatment will depend on the likely cause of your cough.
You will be strongly encouraged to stop smoking if you are a smoker. You will be offered inhalers if you have asthma. If the cough is due to tablets given for high blood pressure, you can switch to another type. If bacterial infection is likely, you may be prescribed antibiotics. A steroid nasal spray may help postnasal drip. Losing weight, cutting out acid foods and alcohol and taking medicine to stop acid in the stomach may all help acid reflux.
You may be referred to a lung (respiratory) specialist for further tests. Most cases will be managed by your GP but you may be referred for further investigation and treatment at a hospital.
What can you do if you develop a cough?
You should call an ambulance if you experience unexpected and severe cough and difficulty in breathing that lasts for more than a few minutes. Otherwise, you should call your GP if concerned.
How can I avoid coughing?
You will need to find the underlying cause and try to address it if possible. Don't smoke, or get help to stop smoking, because all common serious causes of chronic cough are more likely to affect smokers. Try to avoid dusty or smoky places. Use your asthma medication as advised. Avoid over-the-counter cough medicines. You can take paracetamol of ibuprofen for fever and sip fluids if your throat feels sore from coughing. Products that contain codeine may help to stop you coughing but often have unwanted side-effects like constipation and drowsiness.
What is the outlook (prognosis)?
This depends on the underlying cause but is generally very good. People with smoking-related diseases who continue to smoke tend to suffer from coughing and breathlessness. Most coughs are due to short-lived viral infections, do not need special treatment and should be better within a week.