Raneese's case is one of a growing number of serious asthma attacks. While doctors say they have better treatments for asthma than ever before, they are also seeing more asthma episodes requiring hospitalization - and more attacks ending in death.

People with asthma also may be at greater risk of having attacks during stressful times. But while the association between these triggers and asthma attacks has been firmly established, "from a practical point of view," said James McCormick, a professor at the University of Massachusetts Medical School who specializes in lung diseases, "the mechanism by which stimuli like stress {affect asthma} is completely unknown."

Theophylline. These long-acting pills were once the primary medication for asthma. Used to relieve acute attacks, theophylline works to open airways by relaxing the muscles surrounding the bronchial tubes. The drug is related to caffeine and can sometimes cause intestinal problems, headaches and anxiety. When using the medication, blood levels must be carefully monitored to prevent side effects. Because of the growing evidence that the bronchial inflammation is a more important aspect in controlling asthma than the constriction of the airway muscles, theophylline is no longer the mainstay drug, some doctors say.