Most people with persistent asthma rely on inhaled corticosteroids (ICS) to keep their lungs calm and breathing easy. These medications aren’t flashy, but they work. For decades, they’ve been the gold standard for preventing flare-ups. But if you’ve been using them for months or years, you might have noticed a hoarse voice, a fungal infection in your mouth, or unexplained bruising. You’re not imagining it. These are real side effects-and they’re more common than most doctors admit.
The truth? ICS are safe when used right. But when they’re misused, overused, or misunderstood, the risks climb fast. The goal isn’t to stop using them-it’s to use the least amount possible while still keeping your asthma under control. And that means knowing what to watch for, how to reduce harm, and when to ask for help.
What Are the Most Common Side Effects?
The side effects of inhaled steroids fall into two buckets: local and systemic. Local means they happen right where the medicine lands-in your mouth and throat. Systemic means they affect your whole body, even though the drug was meant to stay in your lungs.
Local side effects are the most frequent. Oral thrush (a white, patchy fungal infection) affects nearly half of long-term users. Hoarseness or voice changes happen in about one in three. Throat irritation and coughing are also common. These aren’t dangerous, but they’re annoying enough that many people stop taking their inhaler-sometimes without telling their doctor.
Systemic side effects are rarer, but more serious. They show up mostly with high doses or long-term use. Adrenal suppression-where your body stops making its own cortisol-is a real concern. Studies show fluticasone at doses over 500 mcg/day can suppress cortisol levels twice as much as budesonide at the same dose. That can lead to fatigue, dizziness, or even life-threatening crashes during illness or stress.
Other systemic risks include thinning skin, easy bruising, and bone density loss. In older adults, high-dose ICS increases fracture risk by 31%. In children, long-term use at high doses may slightly slow growth-but studies confirm this doesn’t affect final adult height. For pregnant women, budesonide is the safest choice, with over 15 years of data showing no increased birth defect risk.
Why Do Side Effects Happen?
It’s not the medicine itself-it’s how it’s delivered. When you inhale a steroid, only about 10-20% of the dose actually reaches your lungs. The rest sticks to your throat and tongue. That’s why thrush and hoarseness happen: the drug sits there, killing off good bacteria and irritating tissue.
Some of the drug gets swallowed and absorbed into your bloodstream. That’s where systemic effects come from. Not all steroids are equal. Fluticasone has 30-40% systemic absorption. Budesonide? Only 10-15%. Ciclesonide? Just 2-3%. That’s why switching from fluticasone to ciclesonide can cut side effects by more than half-without losing asthma control.
And here’s the kicker: most people don’t use their inhalers correctly. A PatientsLikeMe study found that 72% of people with side effects had never been shown how to use their device properly. That means they’re getting less medicine in their lungs-and more in their mouth.
How to Minimize Side Effects
There are four proven ways to slash your risk of side effects-without sacrificing asthma control.
- Use a spacer. If you’re using a metered-dose inhaler (pMDI), a spacer is non-negotiable. It holds the puff of medicine so you can breathe it in slowly. Without one, up to 80% of the dose sticks to your throat. With one, lung delivery jumps from 10% to 60-80%. Spacers cut thrush risk by 70%.
- Rinse and spit. After every puff, swish water in your mouth for 10 seconds and spit it out. Don’t swallow. This simple step cuts thrush risk by 50-60% and reduces hoarseness by more than half. Use plain water. Mouthwash isn’t better-and can dry out your mouth, making thrush worse.
- Use the lowest effective dose. GINA guidelines say to start low and stay low. For most adults, that’s 200-400 mcg/day of fluticasone equivalent. If you’re on 1000 mcg/day and your asthma is stable, ask your doctor if you can drop down. Studies show 65-75% of systemic side effects are dose-dependent. You might not even need that much.
- Get your technique checked. Don’t assume you’re doing it right. A 2021 study found that 45-60% of patients had technique errors. A quick 5-minute check with your pharmacist or nurse every 3-6 months can catch mistakes before they cause problems.
Who’s at Highest Risk?
Not everyone faces the same level of risk. Certain groups need extra caution.
Older adults (65+) are more vulnerable to pneumonia, bone loss, and skin thinning. If you’re over 65 and on high-dose ICS (over 500 mcg/day), get an annual skin check and bone density scan if you’ve been on it for more than five years.
Children under 12 on high-dose ICS (>800 mcg/day) have a 2.3-times higher risk of cataracts. That’s rare, but real. Stick to the lowest dose that keeps symptoms under control. Growth delays are temporary and don’t affect final height.
Pregnant women should avoid fluticasone if possible. Budesonide is the only ICS with strong safety data during pregnancy. If you’re planning a pregnancy or just found out you’re pregnant, talk to your doctor about switching.
People with diabetes or osteoporosis should be monitored closely. Steroids can raise blood sugar and leach calcium from bones. Your doctor should check your fasting glucose and bone density if you’re on long-term high-dose therapy.
How to Monitor for Problems
Monitoring isn’t just about blood tests-it’s about noticing changes in your body.
Keep a simple log:
- Any white patches in your mouth? (thrush)
- Is your voice hoarse more than a few days after using your inhaler?
- Do you bruise easily or get cuts that take longer to heal?
- Are you unusually tired, dizzy, or losing appetite?
For high-dose users (over 750 mcg/day for 5+ years), your doctor should order:
- Annual bone density scan (DEXA)
- Annual skin exam for thinning or bruising
- Quarterly check for oral thrush or voice changes
Emerging tools are making monitoring easier. Smart inhalers now track whether you’re using your device correctly and how often. Some can even send alerts to your doctor if you’re skipping doses or using poor technique. In Europe, doctors are starting to use saliva tests to check cortisol levels in patients on high-dose ICS. If your level drops below 3 mcg/dL, it’s a red flag for adrenal suppression.
What If Side Effects Are Already Happening?
If you’ve got thrush, start antifungal mouth gel (like nystatin) right away. Don’t wait. Keep rinsing after every inhaler use. Voice changes usually improve within weeks of lowering your dose or switching to a different steroid.
If you’re bruising easily or feel constantly tired, don’t ignore it. Tell your doctor. You might need a short course of oral steroids to reset your adrenal system-or a switch to a lower-absorption ICS like ciclesonide or mometasone.
Never stop your inhaler cold turkey. That can trigger a life-threatening asthma attack. Work with your doctor to taper down slowly while adding a long-acting bronchodilator (like formoterol) if needed.
The Future: Less Steroids, Better Control
There’s good news on the horizon. New drugs are coming that can replace or reduce the need for steroids.
Biologics like dupilumab and mepolizumab target specific inflammation pathways in severe asthma. In trials, they’ve cut ICS doses by 70% without losing control. If you’ve got severe asthma and are still struggling with side effects, ask if you’re a candidate.
Ultra-low systemic ICS like AZD7594 are in late-stage trials. Early results show 90% less adrenal suppression than fluticasone. These could be available in the next 2-3 years.
For now, the best tool you have is knowledge. Use your inhaler correctly. Use the lowest dose possible. Monitor your body. And speak up if something feels off.
Asthma doesn’t have to mean side effects. With the right approach, you can breathe easy-without paying the price.
Can inhaled steroids cause weight gain?
Inhaled steroids rarely cause weight gain. That’s a common myth from oral steroids, which flood your whole body with hormones. Inhaled steroids are designed to stay in your lungs. Only tiny amounts enter your bloodstream, and even then, it’s not enough to trigger appetite changes or fat storage. If you’ve gained weight, it’s more likely due to other factors like reduced activity from asthma symptoms or medications like oral steroids used during flare-ups.
Is it safe to use inhaled steroids for years?
Yes, if you’re using the lowest effective dose and following proper technique. Millions of people use inhaled steroids for decades with no major issues. The risks rise only with high doses (over 800 mcg/day) or poor use habits like not rinsing after inhalation. Regular check-ups and dose reviews keep you safe. The benefits of preventing asthma attacks far outweigh the risks when used correctly.
Which inhaler has the least side effects?
Ciclesonide and mometasone have the lowest systemic absorption-meaning they’re least likely to cause side effects like adrenal suppression or bone loss. Budesonide is also a good choice, with lower absorption than fluticasone. Fluticasone carries the highest risk of side effects at equivalent doses. Switching from fluticasone to ciclesonide can reduce side effects by 40-60% without losing asthma control.
Can I stop my steroid inhaler if I feel fine?
No. Even if you feel fine, your airways may still be inflamed. Stopping suddenly can trigger a severe asthma attack. Always work with your doctor to taper down slowly. If your asthma has been stable for 3-6 months, your doctor might reduce your dose-but never stop without guidance.
Do spacers really make that much difference?
Yes. Without a spacer, up to 80% of your inhaler dose hits your throat instead of your lungs. That’s why thrush and hoarseness happen. With a spacer, you get 60-80% of the dose where it’s supposed to go-and 70% less in your mouth. Spacers cut side effects in half and make your inhaler work better. They’re cheap, reusable, and should be used with every pMDI.