TL;DR
Inhaled steroids have long been known to suppress adrenal function, especially at higher doses. Newer research shows that adrenal insufficiency is more common in asthma patients than previously thought—sometimes even in those not taking oral steroids. High-dose inhaled steroids, frequent steroid “bursts,” and total steroid exposure relative to body weight are all linked with an increased risk. Patients with adrenal suppression often feel worse, even when lung tests look normal.
Early Research on Steroid Use in Asthma & Adrenal Suppression
We have known for decades that inhaled steroids used by asthma patients can lead to adrenal suppression. A study published in 1993 looked at children who were taking 400 micrograms of steroids per day. The subjects of the study were 49 children who had a mean age of 9.2 years, taking budesonide and 28 children with a mean age of 10.2 years taking beclomethasone dipropionate. They were compared to 23 children without asthma, who had a mean age of 8.9 years. Cortisol concentrations were lower in the children using the steroids than they were in the non-asthmatic controls [1].
Corticosteroids & Adrenal Suppression: Newer Research
In one study, a group of severe asthma patients, 1 in 4 had low morning cortisol levels that suggested undiagnosed adrenal insufficiency. Not surprisingly, the patients who used daily oral steroids had the highest risk: 60% of them had adrenal insufficiency. But the surprising part was that 17% of patients who were NOT taking oral steroids (and hadn’t taken any in the past 2 weeks) also had cortisol levels that suggested adrenal insufficiency.
The study also found that people who used occasional “burst” steroid treatments while on high-dose inhaled steroids had a higher risk of adrenal problems. Each steroid “burst” increased the risk a little more. Even after taking oral steroid use into account, higher doses of inhaled steroids alone were still linked to an increased risk of adrenal insufficiency. This risk became even clearer when the total steroid dose was adjusted for the patient’s body weight — meaning that heavier exposure relative to weight raised the risk the most.
Patients who had adrenal insufficiency reported worse asthma symptoms, even though their lung tests and inflammation measurements looked similar to the patients whose adrenal glands were still working normally [2]. Other research has produced similar results [3-5].
What Are the Symptoms of Adrenal Suppression?
Symptoms of adrenal suppression include chronic fatigue, muscle weakness, and weight loss. Other signs are low blood pressure, especially upon standing, which can cause dizziness or fainting. Skin changes like darkening, particularly in scars and moles, can also occur, along with cravings for salt. Severe cases can lead to Addison’s Disease. NIH
FAQs
Can inhaled steroids really affect the adrenal glands?
Yes. While inhaled steroids are safer than oral steroids, high doses can still suppress the adrenal glands, especially when used long-term.
Do only people taking oral steroids get adrenal insufficiency?
No. New research shows that even patients who aren’t taking oral steroids can develop adrenal suppression if they use high-dose inhaled steroids.
What are the symptoms of adrenal suppression?
Common symptoms include fatigue, weakness, dizziness, low blood pressure, poor stress tolerance, and salt cravings. Severe cases may progress to adrenal crisis if untreated.
How common is adrenal insufficiency in asthma patients?
About 1 in 4 patients with severe asthma may have undiagnosed adrenal insufficiency, according to newer studies.
Why do some patients feel worse even when their lung tests are normal?
Adrenal suppression affects the whole body. Even if the lungs look stable, low cortisol levels can make patients feel tired, weak, or symptomatic.
Should asthma patients stop their steroids?
No. This article is educational only—not medical advice. Changes to steroid use should always be made with guidance from doctors trained in natural healthcare.
References:
- Thorax (1993;48:599-602) Effects of high doses of inhaled corticosteroids on adrenal function in children with severe persistent asthma.
- The Journal of Allergy and Clinical Immunology: In Practice June 10, 2022. Adrenal insufficiency in asthma is due to combined steroid burden
- Nature Medicine 21 March 2022. Metabolomic profiling reveals extensive adrenal suppression due to inhaled corticosteroid therapy in asthma.
- The Contribution of Oral and Inhaled Glucocorticoids to Adrenal Insufficiency in Asthma
- BMC Pediatr. 2019 Nov 5;19:411. Effect of long term inhaled corticosteroid therapy on adrenal suppression, growth and bone health in children with asthma
