Get the most out of your peak flow diary

Facts | 1/3/2019
Get the most out of your peak flow diary
Living with asthma can have its ups and downs. By measuring your peak flow, you can track your symptoms so that both you and your doctor can better understand what’s normal for you and keep your asthma under control.

Every body is different. And every person living with asthma experiences it differently. As asthma is a variable condition, its symptoms may change with the seasons and life events. That’s why measuring your peak flow and keeping track of any symptoms you have can be so useful.

A peak expiratory flow, PEF, tells you how quickly you can blow air out of your lungs, giving a good overview of the wellbeing of your lungs. This is often tracked during the asthma diagnosis period, but it’s still a good idea to keep a peak flow diary after the diagnosis to make sure your asthma is well managed.

A bridge between you and your doctor

Using a peak flow diary helps both you and your doctor keep better track of your health. It offers a good overview of your asthma control and lifestyle and shows how well your medicines are working.

“A peak flow diary can really bridge the conversations between you and your medical provider as there’s evidence of your peak flow,” says Dr. Andy Whittamore, General Practitioner and Clinical Lead for Asthma UK.

Getting to know your normal peak flow score, which depends on your age, sex and height, will offer you a good guideline, too.

“Knowing what to do if there are changes in your symptoms or peak flow will help you recognise that you have power over your condition,” Dr. Whittamore points out, noting that the readings you get in a doctor’s office after using your inhaler often might differ from those you get at home.

Measuring peak flow properly

A peak flow is measured by using a peak flow meter which you can obtain from your medical provider or pharmacy.

In order to find out your peak flow scores, you blow into the meter twice a day and record the best score out of three tries. Then write these scores down, along with any symptoms you might be feeling, like shortness of breath, wheezing, a cough or tightness in your chest.

During a time of severe inflammation, the amount of air measured would be much lower than when your airways are clear. “A highly variable peak flow is as much a sign of struggling to keep your asthma under control as is a continuously low peak flow,” Dr. Whittamore explains.

A diary can also serve as a way for your doctor to see how frequently you rely on your relief inhaler. “We know that if someone is using their reliever three or more times per week, it is a sign that there is untreated inflammation that needs attention,” he says.

Part of a self-management plan

But the diary is as much for your own peace of mind as it is a track record for your doctor. You can notice if your peak flow score dips below 80 per cent and take action according to your personalised plan.

“Having a written asthma self-management plan is so important,” says Dr. Whittamore. That unique action plan, drawn up by your doctor during a visit, should list what you should do if your peak flow dips, whether that is taking medicines or seeking medical attention. “People with asthma are four times less likely to end up in hospital if they know what to do.”

Although not everyone likes to keep diaries, this personalised documentation is a great way to have power over your condition.


By Courtney Tenz

Photo by iStock


Asthma UK provides advice and guidance to people with asthma through its website and nurse-staffed telephone helpline, and funds research into a cure for asthma. For more information on peak flow, visit

Find more information on peak flow on Asthma UK’s website.

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Orion Corporation is a globally operating Finnish pharmaceutical company. We develop, manufacture and market human and veterinary pharmaceuticals and active pharmaceutical ingredients. The dry powder inhaler developed at Orion is in the core of our respiratory therapy area.