Control of asthma is enhanced when careful consideration is given to underlying mechanisms. Patients can be advised of ways to avoid or minimize contact with offending allergens, and, in some cases, pharmacologic management may not be necessary. Care must be taken when treating patients with concomitant disorders, such as hyperthyroidism. Also, psychological factors may have a role in exacerbating symptoms in suggestible patients. Noncompliance, in some cases due to inability to pay for medication, may be an unrecognized cause of treatment failure.