According to the U.S. National Center for Health Statistics, in 2002:¹

• 30.8 million people reported that they had at one time been diagnosed with asthma.
• Of those who were diagnosed with asthma, 20 million reported that they still had it. Of these, 6.1 million were children and 14 million were adults.
• 12 million people reported having had an asthma attack during the previous 12 months. In other words, about 60% of the people who had asthma at the time of the survey had had an asthma attack in the previous year.
• There were 1.9 million visits to the hospital emergency room for asthma. Children age 4 and younger had to go to the emergency room the most often.
• About 4,000 people died of asthma.

Although many people with asthma suffer from poorly controlled symptoms, evidence suggests that when taken correctly, currently available medications are very effective in controlling symptoms in the majority of people with asthma.