Asthma sufferers have an asthma action plan with a stoplight system to help recognize and respond to changes.

"Management of acute loss of asthma control in the yellow zone: a practice parameter," is published in the August issue of Annals of Allergy, Asthma and Immunology, the scientific publication of the American College of Allergy, Asthma and Immunology (ACAAI).
The practice parameter was developed for providers to help their asthma patients understand what to do in the yellow zone to prevent moving into the red zone. The recommendations are intended to help patients recognize and treat acute loss of asthma control. They apply to the home setting only; not providers' offices, emergency departments or hospital settings. The ideal intervention, according to the new parameter should "provide quick relief of symptoms, prevent progression to the red zone, be safe enough to initiate at home, be convenient and practical for self-administration, be portable so that it is always available and be cost-effective."
Source-Eurekalert