How to keep an asthma diary

It supports, but does not replace, a written asthma action plan. The diary supplies observations for routine appointments; the action plan tells you what to do as asthma improves or worsens.

Write down daytime and night-time cough, wheeze, chest tightness or breathlessness, along with any effect on sleep, exercise, school or work. Include reliever and controller use, missed doses, and whether each treatment helped.

Possible exposures add context: respiratory illness, smoke, dust, pets, strong scents, weather changes or physical activity. If your clinician has asked you to measure peak flow, record the reading and the time, using the same meter and technique. Do not compare your result with another person's target.

Choose a format you can maintain, such as paper notes, a calendar or a phone entry. Record events soon after they happen and use consistent descriptions. Bring the diary, your action plan and all inhalers to reviews so the clinician can connect symptoms with treatment and technique.

Look for repeated night waking, activity restriction, clusters after a particular exposure, or increasing reliever use. These patterns merit a treatment review; they are not a reason to change prescribed doses without guidance. Also check whether nasal allergy symptoms occur alongside asthma difficulties.

Do not pause to complete the diary if you have severe breathlessness, cannot speak comfortably in full sentences, develop blue or grey lips, feel confused or very drowsy, or fail to improve after the emergency treatment directed in your action plan. Seek urgent medical help and take your prescribed reliever as instructed.

Ask whether the pattern suggests poor control, an avoidable trigger, incorrect inhaler technique or another cause of cough. Confirm your personal peak-flow zones if monitoring is recommended, and ask which diary changes should lead to a routine appointment, same-day advice or emergency care.