Many people with asthma have two inhalers, and it is common to be unsure which is which. One gets used whenever you're wheezy. The other sits in a drawer on good weeks and comes out when things get bad. If that sounds familiar, the drawer one is probably the one that was meant to be used every day.
This guide explains what the two kinds of inhaler do, why the everyday one matters most on the days you feel fine, and how to keep track of puffs so neither runs out when you need it. It is general information. Your own inhalers, doses and plan come from your doctor, nurse or pharmacist, and they are the people to ask about changing any of it.
Two jobs, two inhalers
Asthma involves two things happening in the airways. There is inflammation, a longer-lasting swelling and sensitivity of the airway lining. And there is tightening, when the muscles around the airways squeeze and make breathing hard. Most asthma inhalers are aimed at one or the other.
The reliever (rescue) inhaler
A reliever works on the tightening. It relaxes the airway muscles quickly, usually within minutes, so it is what you use when symptoms start: coughing, wheezing, a tight chest, shortness of breath. In the UK relievers are commonly blue; in the US they are often called rescue inhalers.
The NHS describes relievers as inhalers you use when you get symptoms. They do not treat the underlying inflammation, which is why they are not the whole answer.
The controller (preventer) inhaler
A controller works on the inflammation. Most contain a low dose of an inhaled corticosteroid, sometimes combined with a long-acting medicine that keeps the airways open. Americans tend to say "controller"; the NHS says "preventer". It's the same idea.
A controller does not give quick relief. It works gradually, by calming the airways over time so they react less to triggers like colds, pollen, smoke or exercise. That is why it is taken every day, usually at set times, as your doctor has prescribed.
Inhalers that do both
Some people are prescribed a single inhaler that works as both a daily controller and a reliever. The NHS calls this maintenance and reliever therapy (MART). If you're on one of these, your asthma action plan will say how to use it day to day and how to use it when you have symptoms. Follow that plan rather than the general description above.
Why the controller matters when you feel well
The most common way a controller stops working is that people stop using it. It is easy to understand why. You feel fine, the reliever is what makes you feel better, and the controller doesn't seem to do anything you can notice.
But feeling fine is often what the controller is doing. The inflammation it keeps down is not something you feel until it builds up. Stopping the controller on good days can let it creep back, so the next cold or high pollen day hits harder.
The NHS advises using your preventer every day even when you feel well, and not stopping without talking to your GP or asthma nurse. The same is true in US guidance from the National Heart, Lung, and Blood Institute: long-term control medicines are taken daily to prevent symptoms.
If a controller is causing side effects, such as a sore mouth or hoarse voice, tell your doctor, nurse or pharmacist. Rinsing your mouth after using a steroid inhaler, or using a spacer, is often recommended for this, and there may be other options. The fix is a conversation, not quietly skipping it.
Your reliever use is a signal
Needing your reliever more often than usual is one of the clearest signs that asthma is not well controlled. The NHS advises seeing a GP if you need your inhaler more often than usual or your symptoms stop you doing your normal activities.
This is one of the best reasons to keep track of reliever use. If you notice you are using it more than you used to, or you're waking at night with symptoms, tell your doctor or asthma nurse. It is often a sign the treatment plan needs reviewing, not a sign to just carry on with the reliever.
If your symptoms are severe, your reliever isn't helping, or you're too breathless to speak, follow the emergency steps in your asthma action plan and get urgent help.
Get an asthma action plan
An asthma action plan is a written plan, made with your doctor or nurse, that says:
- Which inhaler is which, and what each one is for.
- Your daily routine for the controller.
- What to do when symptoms get worse, step by step.
- When to get urgent help.
The NHS and NHLBI both recommend one. If you don't have a plan, or it is years old, ask for it at your next review. Keep a copy on your phone and one at home, and give one to anyone who helps look after you or your child.
Keep track of puffs and refills
Both inhalers can run out, and they run out differently.
- The controller is used on a schedule, so how long it lasts is predictable. Puffs left, divided by puffs per day, gives you roughly how many days are left.
- The reliever is used as needed, so it's less predictable. It can go months untouched and then empty in a bad week.
A few things make both easier:
- Use the dose counter, if your inhaler has one. It's more reliable than guessing, and priming puffs count too.
- Write down the start date on the inhaler or in your phone when you open a new one.
- Reorder the controller before it's empty. A week or more of buffer covers weekends and delays.
- Keep a reliever where you'll need it, and check it hasn't expired or run low.
The guide to how long an inhaler lasts goes through counters, priming and estimating a reliever in more detail. The inhaler days calculator takes the puffs left and puffs per day and gives you the last full day and a date to reorder.
Build the controller into your day
Because the controller is taken on a schedule, it helps to attach it to something you already do, like brushing your teeth morning and evening. That has a bonus: a steroid inhaler is often followed by rinsing your mouth, and you're at the sink anyway.
A reminder can help too. Doz doesn't count puffs, but it can remind you when a scheduled dose is due, including through Silent mode with Critical Alerts, and send a follow-up nudge if a dose stays unlogged. For the count itself, rely on the inhaler's counter.
Frequently Asked Questions
What is the difference between a controller and a reliever inhaler?
A reliever relaxes the muscles around the airways quickly, so it is used when symptoms start. A controller, also called a preventer, reduces the inflammation in the airways over time, so it is used every day to prevent symptoms. Some people use a single inhaler that does both, as their action plan describes.
Should I use my controller inhaler if I feel fine?
Yes, if that's how it has been prescribed. Controllers work gradually and only while you keep using them, so feeling fine is often a sign they are working. Talk to your doctor or asthma nurse before stopping or changing how you use it.
Is it bad to use my reliever inhaler a lot?
Needing your reliever more often than usual is a sign your asthma may not be well controlled. The NHS advises seeing a GP if you're using your inhaler more often or symptoms are affecting your usual activities. Your treatment plan may need reviewing.
Can I use my reliever instead of my controller?
Not as a substitute. A reliever eases symptoms but doesn't treat the underlying inflammation. The exception is an inhaler prescribed for maintenance and reliever therapy, which is designed for both jobs. Follow your action plan and ask your doctor if you're unsure which you have.
How do I know when my inhaler is running out?
Check the dose counter if it has one, and the leaflet explains how it works. For a controller, divide the puffs left by the puffs you use each day to estimate the days left. The inhaler days calculator does this and gives a reorder date.
Where to start
Take out every inhaler you have and check which is the controller and which is the reliever. Read the dose counter on each. If you're not sure which is which, or you don't have an asthma action plan, ask your pharmacist or book a review with your asthma nurse.
Sources
- NHS, Asthma: Treatment
- National Heart, Lung, and Blood Institute, Asthma: Treatment and Action Plan
- MedlinePlus, Asthma - control drugs
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