Asthma diagnosis could depend on the time of patient's appointment, new research shows

People with severe asthma may get a different assessment from their doctor if they have an appointment in the morning, according to new research published in the American Journal of Respiratory and Critical Care Medicine.

The study of more than 300 people with asthma, conducted by researchers at the University of Manchester and part-funded by Asthma UK, found the human body clock has a significant impact on the way doctors can diagnose and potentially treat asthma.

Researchers examined the sputum samples – a mixture of saliva and mucus coughed up from the respiratory tract – of asthma patients. Sputum is key to understanding how to diagnose and treat people with severe asthma as it contains inflammatory cells – known as eosinophils. In general, the higher the amount of eosinophils, the worse someone’s asthma is.

The study found that people with asthma who were seen in morning clinics were more than twice as likely to have more inflammatory cells in their sputum than those who were seen in afternoon clinics.

The research appears to show that people with severe asthma who saw their doctor in the morning could be treated for a more acute condition, compared to if they saw a clinician in the afternoon. While more research is needed to determine whether their morning assessment is more accurate than their afternoon assessment, it could be crucial when deciding what course of treatment they should undertake.

Dr Samantha Walker, Director of Research and Policy at Asthma UK said:

“This is an exciting preliminary study that reveals how powerful the body clock can be. If doctors and nurses know that the time of day can affect someone’s asthma they will be able to diagnose and treat them more effectively.

“Around 5.4million people in the UK have asthma and it can have a huge impact on their life, leaving them gasping for breath and at risk of a potentially fatal asthma attack. But asthma is a chronic condition with complex causes and triggers that can differ from patient to patient. More research into better ways of diagnosing asthma is urgently needed to develop better tests and to help develop more targeted treatments. For more information on how Asthma UK is supporting research and to get involved visit”


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About Asthma UK:

  • In the UK, 5.4 million people are currently receiving treatment for asthma: 1.1 million children (1 in 11) and 4.3 million adults (1 in 12).
  • Every day, the lives of three families are devastated by the death of a loved one to an asthma attack, and tragically two thirds of these deaths are preventable.
  • Asthma UK’s mission is to stop asthma attacks and cure asthma. We do this by funding world leading research, campaigning for improved care and supporting people to reduce their risk of a potentially life threatening asthma attack.
  • The Asthma UK Helpline is open weekdays from 9am to 5pm on 0300 222 5800.
  • For more information about asthma please visit