Although asthma is defined as a chronic (i.e. long term) illness, it is not usually life threatening - and for most sufferers becomes more of an annoyance than a genuine threat to their well-being. As one of the most common non-life-threatening illnesses in the world, asthma is well studied by medical research scientists, and as a result there are several treatments available.
By far the best known asthma treatment is via medicine inhalation. The primary medicines used in inhalers are beta-2 agonists (for relieving an acute attack of asthma) and corticosteroids (for preventing attacks). These medications come in a variety of doses depending on the severity of the sufferers' condition, and are inhaled directly in to the lungs using an inhaler (sometimes known as a 'puffer'). As these treatments go directly to the source of the issue by entering the lungs immediately, they have long been proven to be the most effective asthma treatment.
Another option is steroid treatment, usually in tablet form. However, a course of steroids is usually only ever prescribed following a severe asthma attack - usually of the kind of severity that results in hospitalization The vast majority of sufferers will never need anything beyond their combination of inhalers to deal with their illness.
The concluding option is also only used in the case of a severe attack, though is an option during the attack rather than following it. Nebulizers create a mixture of water and air, through which one can inhale a purer form of the usual medication used in inhalers. Nebulizers tend to be carried on emergency calls and at hospitals, though some sufferers' of extremely severe asthma may be offered one at home.