How long does an asthma flare up take to resolve?

No one knows how long an asthma attack lasts

No one knows how long an asthma flare up lasts. Asthma flare ups are also known as asthma attacks or an asthma exacerbation. Asthma exacerbations and hospital admissions can be prevented by anti-inflammatory treatment. Well controlled asthma should not flare up.

Doctors often treat attacks for a fixed time period

No one knows how long an asthma attack takes to resolve. However health professionals often treat attacks as if they do! Most asthma guidelines recommend oral corticosteroid treatment for attacks. The UK SIGN Guideline states very clearly that these corticosteroids should be continued until the attack resolves. From my knowledge, most people are treated for attacks with fixed corticosteroid courses of 3, 5 or 7 days. How do these doctors & nurses know the attack will be over in 3, 5 or 7 days?’

Oral corticosteroids should be continued as long as an attack lasts

According to the United Kingdom (BTS/SIGN) Asthma guideline section on treatment of acute asthma attacks/ Flare ups / exacerbations:

  • In Adults: Continue prednisolone (40–50 mg daily) until recovery (minimum 5 days).
  • In Children: Treatment for up to three days is usually sufficient. But the length of course should be tailored to the number of days necessary to bring about recovery. Tapering is unnecessary unless the course of steroids exceeds 14 days.

So the key message is that oral corticosteroids should be continued until the attack is over. The excellent acute asthma section (chapter 9) in the 2019 version of the BTS/SIGN Guideline is essential reading. To download it click here.

How to tell if an asthma attack is over

It may take days or weeks for an asthma flare-up to resolve. An asthma flare up or attack is over when a person is free of symptoms. An asthma attack is not over yet If rescue reliever medication is needed. When the Peak Expiratory Flow or Spirometry has returned to the patients usual best level the attack is over. Therefore treatment for attacks should continue until the attack has resolved.

Asthma is a chronic ongoing disease – not an acute disease

Asthma is a chronic ongoing disease, nonetheless it is often treated as if it is an acute illness. The attack is usually treated very well although, surprisingly, a large majority of these people are not followed up for a review to identify and deal with any modifyable features.

An asthma flare up or attack means something has gone wrong

Someone whose asthma is appropriately treated with preventer medication, should be free of attacks, and therefore an attack signals a failure of treatment. In addition, asthma attacks are a well known risk factor for future attacks and therefore people are most vulnerable after an attack.

It follows that clinicians should aim to ensure that after asthma attacks are resolved that any modifiable factors are identified and dealt with to try and prevent another attack. Listen to my asthma podcast (second from bottom) here. This is one of the two main purpose of a post attack review.

Post asthma attack reviews

The purpose of the post attack review is:

i) to assess the progress of the current attack to determine the need for treatment. Including:

  • assessing current symptoms for example using the Asthma Control Test (ACT),
  • requirement for reliever treatment,
  • night time symptoms including waking due to asthma
  • lung function (Peak Flow or spirometry).
Peak flow chart showing when an attack was over
Peak flow chart showing resolution of an asthma attack. This woman presented for the first time with an asthma attack. I did not know what her normal peak flow was so we used a peak flow chart to inform us when it would be safe to stop her oral corticosteroids

ii) to identify modifiable risk factors causing the attack and optimise care. Modifiable risk factors include:

  • failure by doctors to prescribe controller medication (mainly inhaled corticosteroids);
  • failure by patients to refill prescriptions for controller medication,
  • excess reliever prescriptions and over-reliance by patients on these.
  • For more information on modifiable risk factors see GINA Table 2-2 and Table 11 (page 82)  in the BTS/SIGN Guideline).

More details on post attack reviews here.


Keep patients safe and reduce GP’s workload by using post attack reviews to maintain asthma control.

An asthma attack signals something needs to change. Identifying modifiable risk factors and dealing with them will reduce future attacks. This will help to prevent asthma flare ups, hospital admissions and avoidable deaths. When should post asthma attack reviews be done? Ideally before the oral corticosteroids run out or within a week. Many primary care colleagues argue that this is not feasible due to heavy worlkload. A practical solution is to simply block off one appointment every afternoon for a post asthma attack review. If not taken up by midday it could be used for another patient that day.

Leave a Reply