Asthma is a chronic lung disease affecting people of all ages. It is caused by inflammation and muscle tightening around the airways, which makes it harder to breathe. Symptoms can include coughing, wheezing, shortness of breath and chest tightness. These symptoms can be mild or severe and can come and go over time. Although asthma can be a serious condition, it can be managed with the right treatment. People with symptoms of asthma should speak to a health professional.