Hypothalamic-pituitary-adrenal axis suppression, or HPA axis suppression, is a condition caused by the use of inhaled corticosteroids typically used to treat asthma symptoms. People with this condition cannot produce enough cortisol, which is vital when the body is under stress, according to the Allergy, Asthma & Clinical Immunology Journal.
HPA axis depression can continue for up to a year after stopping inhaled corticosteroid therapy. If left untreated, HPA axis depression can lead to a significant feeling of unwellness and can even cause death in severe cases, according to the Allergy, Asthma & Clinical Immunology Journal. Using the lowest dose of an inhaled corticosteroid lessens the risk of HPA axis depression.