Asthma affects 300 million people worldwide out of a total population of 6 billion, and 30 million people in the United States out of a total US population of 1.4 billion. An asthma attack can be triggered by allergens like pollen, dust, pets, perfumes, smoke, and paint, and symptoms include coughing, heavy breathing, and chest pain. Relaxation techniques like belly breathing where one imagines their lungs filling like a balloon can help alleviate asthma symptoms during an attack.