PEFLog user instructions

Using PEFLog is easy and it supports you in ensuring your asthma is under control. Use your asthma meter according to instructions and then save the provided values into PEFLog asthma tracker app.

Using a PEF meter

A peak flow meter is an inexpensive, portable, handheld device used to measure how well air moves out of the lungs. Measuring and monitoring your peak flow using the meter is an important part of managing asthma.

PEF reporting is easy

There are just three simple steps in managing asthma. Use your PEF meter according its instructions to get the results and save them to PEFLog and inspect results or send PEF reports to your own doctor.


  • Your data is controlled only by you and nobody else can access it and we don't share it with 3rd parties

  • PEFLog4 stores data securely and safely into your own user account when you login with email, Google or Apple accounts (iOS devices). Data is synchronised automatically between all your devices, so there is no need for backups

  • PEFLog3 stores data both into your device and keeps it safe in your own user account when you login with email, Google or Apple accounts. So, there is no need for manual data backups any longer. It is very easy to restore data or synchronise data to your secondary device when you login with the same account than the data was created with

Note! If you haven't yet upgraded to PEFLog4, then see the PEFLog3 user instructions

Save the PEF values

Set the three values provided by PEF meter into PEFLog. You can also provide additional information like e.g. occasion (work, travel…) and other comments in order to figure out if certain occasions correlate with a PEF values.

  • Blow three consequent times to the peak flow meter

  • Set three results in the application and press Save before medication

  • Optionally, if you’re diagnosing asthma then do following after the previous step

    • Take the prescribed medication and wait 15-20mins (Note! 15min timer may be useful reminder)

    • Blow three consequent times again and then set three results in PEFLog and press Save after medication

  • Repeat every morning and evening at the same time and additionally during the day when needed

  • Note! Occasionally you might want to save used medication when the PEF meter is not at hands. Then press Save only medication which allows to save medication and comments without PEF readings.

Check the report

PEFLog reports provides invaluable information about asthma status. There is lot of important information available about asthma e.g. by Asthma and Allergy Foundation of America

The application draws the chart of the measurements and indicates alarming daily variation (>20%) with red colour. It’s easy to check and share the report any time (for instance after the monitoring period).

You can zoom the report by pinch-zooming and pan it by tap-and-move. You can also select the data range by tap-and-hold and then move to another date. If you have zoomed the chart, then you can quickly scroll or zoom out by using touch sensitive areas at the bottom of the chart. Pressing PDF icon will prepare a report ready to be shared. The report includes the chart, additional information and detailed results.

Note! Bronchodilatation is calculated when the duration between the puff without medication and the time with medication is less than one hour.

In order to take a deeper look at the report, you can rotate the device and turn into a landscape mode. Landscape mode is optimised for viewing the report and it occupies whole screen.

Color zones

Color zones in the chart

The color zones illustrated in the chart can be used to show you the effectiveness of your breathing. Ideally, your PEF trend should remain in green zone. The zones are based on the personal best PEF. Note! The personal best reading is calculated automatically if not provided manually in the My Details -page. If you provide personal best value manually then the color zones are based on it.

Green: 80-100% of your personal best

  • Your breathing is good and you do not have any early warning signs or asthma symptoms

Yellow: 50-80% of your personal best

  • Caution

  • Symptoms could be runny and stuffy nose, feel more tired, chin or throat itches, restless, coughing, dark circles under your eyes

  • Recheck peak flows after 20-30 minutes and call your doctor, healthcare professional, or nurse care manager if your peak flow is not back to the Green Zone

Red: Below 50% of your personal best

  • Danger

  • Symptoms could be cough more at night, wheezing, chest feels tight or hurts, breathing faster than normal

  • You should use your quick-relief medicine by inhaler or nebulizer right away and call your doctor

Colors in the Log-page

Readings are illustrated in green except when too much (80%) below the best reading so far. Note! The best reading is calculated automatically if not provided manually in the My Details -page.

For instance, if the new reading goes below 80% the best reading so far, then the color of the new reading is yellow. On the other hand, if the new reading is above the best reading so far, then the color of the new reading is green but all future readings will be compared against the new reading. I.e. the new reading becomes the new best PEF.

This logic is especially relevant for children because their PEF readings often improve as the child grows. The continuous improvement of PEF readings doesn’t mean that past readings suddenly become any worse and color should change. So, green readings in the past should remain green regardless if future readings become higher.

This logic means that the color of the readings is always determined by the current situation and the best PEF before it. The logic is applied in the Log-page and all PEF readings are taken into account.


  • The chart in the report-page presents color zones in relation to the all time best

  • Log-page presents colors in relation to the previous best

  • In both cases, the personal best provided manually in My Details-page is taken into account if it's provided

Modify readings

Tapping titles collapses (closes) and uncollapses (opens) the groups. The arrow on the right side indicates if the group is collapsed or not. Tapping the item will allow you to delete or modify it.

CSV files

You can export data to a CSV file for e.g. inspecting and analysing it with your computer's spreadsheet program. It is also possible to try to import CSV file that contains readings, but the format of the CSV must be exactly such that PEFLog understands it. CSV files can also be used as a backup if you use the application without logging in. When you log in with Email, Google or Apple (iOS devices) account, then there is no need for backups because the data will always be synchronised to all your devices where you log in to PEFLog using the same account.


date, "[puff1, puff2, puff3]", medication yes or empty, "[occasion1, occasion2, etc]", "[comment1, comment2, etc]"


2022-01-20 22:40:00.000, "[625, 630, 625]", Yes, "[Home, Evening]", "[Seretide, Fluticasone]"