Asthma is defined as variable airflow limitation, with variable respiratory symptoms, which may include cough, chest tightness, shortness of breath and wheeze. Asthma onset can be at any age. Asthma is usually reversible, but may become irreversible if it is inadequately treated.
Your doctor may diagnose asthma based on your history, but to support the diagnosis of asthma you will need a breathing test, and if this is normal you may need a Bronchial Provocation Test, which is preformed in a lung function lab.
If you are diagnosed with asthma you will most likely need to be on a regular preventer puffer, and a reliever as necessary. If you have very infrequent symptoms you may only need a reliever as necessary.
If your asthma is poorly controlled and you are having symptoms or using the reliever more than twice a week, there are various triggers that may be contributing, and it may be a good idea to see a respiratory specialist to get your asthma back under control.