But i heard that inhaled steroids for asthma treatment have dangerous side effect to overall health.

Not necessarily : Thouhg taking steroid orally or by injection can have long term effects, inhaled steroids allow very little steroid absorption into the blood stream. The most common side effects of inhaled steroids are fungal infections in the mouth/throat (rinse your mouth after every treatment) or maybe a bronchospams if you use a powder inhalation. Talk it over with your physician or pharmacist.

Necessary: for persistent or moderate Asthma for reducing inflammation and decreasing frequency of asthma attacks. Actually has safer profile than systemic steroids