Asthma is caused by a combination of genetic and environmental factors. While it is inherited and runs in families, asthma is triggered by things in the environment like allergens, smoke, and mold. It is not communicable but anyone with the asthma gene can develop symptoms, though it is more common in children. Symptoms include coughing, wheezing, chest tightness, and shortness of breath that vary between individuals. Doctors diagnose asthma through medical history questions, physical exams, and lung function tests. Asthma is a lifelong condition but symptoms may improve during teenage years, though patients should still have access to inhalers in case of attacks. It affects the airways, lungs, and breathing muscles.