To diagnose asthma and develop a treatment plan, your primary care specialist reviews your symptoms and medical history and completes a physical examination. They listen to your breathing and have you undergo lung function tests to assess your ability to get a full breath of air. Spirometry is a test that determines how fast you can breathe out and how much air you can exhale after a deep breath. Peak flow tests measure how hard you can breathe out. You might complete lung function tests before and after taking medications that open your airways. Your family physician may recommend you undergo allergy testing, imaging procedures, or other diagnostic tests.