The muscles of bronchial walls tighten, and extra mucus is produced. Airflow out of your lungs is diminished, often causing wheezing. About 10 percent of children and 5 percent of adults in the United States have asthma. About half of the children who have asthma develop the condition before age 10. Asthma is usually an inherited condition, and it is not contagious.
Asthma attacks can range from very mild to life-threatening.
They can last for just a few minutes, or they can go on for hours and even days. Asthma attacks can also be triggered by exposure to substances in the home or workplace. Some people are more prone to suffer an asthma attack after exercise, especially if they exercise in cold air. Respiratory infections caused by colds and the flu can aggravate the symptoms of asthma. These preservatives are sprayed on vegetables and fruits by restaurants and stores to keep them from turning brown.