 This research study is being done to learn more about severe asthma by comparing people with severe asthma to those with milder forms of asthma and people without asthma, at baseline and over time. Individuals are being asked to join a research study to help understand the differences in the lungs and blood of participants with severe asthma compared to those with milder asthma and healthy individuals, as well as differences in overall health. Investigators also want to determine whether these differences predict asthma-related and biologic outcomes over 1 year of follow up. 