Asthma is a common respiratory condition that affects people of all ages, and can have a significant impact on daily life. Symptoms can be triggered by various factors, including allergens (such as pollen, pet dander, and dust mites), respiratory infections, air pollution, cold air, exercise, and certain medications or chemicals. Common symptoms of the condition include wheezing, coughing (especially at night or early morning), chest tightness, and shortness of breath.