Asthma causes inflammation of the small airways in the lungs, making them narrow and causing excess mucus production. Symptoms include cough, wheezing, shortness of breath, and chest tightness. Asthma attacks can be triggered by pollen, dust, mold, animal dander, smoke, fumes etc. Many people with asthma also have allergies. Allergy symptoms - runny nose, stuffy nose, coughing, sneezing, wheezing, rashes, tiredness, headache - happen when your immune system overreacts to an allergen. Also see nasal allergies and food allergies.