The ALA-LHC is a longitudinal, multi-center cohort study that will enroll approximately 4,000 young adults between the ages of 25-35 who do not have severe lung disease.  The overarching objective of the ALA-LHC is to establish a national cohort of young adults for the purpose of defining lung health and developing targets to intercept chronic lung disease at its earliest stages. The scientific goal of the study is to establish the relationship between a variety of factors (lifetime environmental exposures, fitness and physical activity, biomarkers, nasal respiratory epithelial transcriptome) and ideal versus impaired peak lung health (reserve and markers of susceptibility in our model) in young adulthood.

1. Inclusion
   1. Age 25-35 years at the time of the enrollment
   2. Able to read and understand English or Spanish
   3. Has and is willing to share a social security number
   4. Resident (citizen or non-citizen) of the United States (US) for at least 12 months prior to examination. 
   5. Willing to provide contact information for at least 2 proxies who are likely to know the whereabouts and vital status of the participant
2. Exclusion
   1. Severe asthma, which is defined as any of the following:
      1. Current (i.e. at the time of the visit) GINA Step 4 or higher therapy (medium dose ICS/LABA or high dose ICS or add-on LAMA; Medium dose = >250 fluticasone, propionate =100 fluticasone furoate, >200 beclomethasone, >400 budesonide, >220 mometasone). We will accept low-dose ICS/LABA or medium dose ICS
      2. OR 3 or more unscheduled healthcare visits (provider/urgent care/ER) for asthma in the past 12 months
      3. OR One asthma hospitalization in the past 12 months
   2. History of any chronic lung disease other than asthma including but not limited to COPD, cystic fibrosis, pulmonary fibrosis, pulmonary hypertension
   3. Current pregnancy
   4. History of cancer other than non-melanoma skin cancer
   5. Diagnosed cardiovascular diseases (i.e., congenital heart disease, coronary heart disease)
   6. Inability to comply with study procedures, including
      1. Inability or unwillingness to provide informed consent
      2. Inability to perform study measurements
      3. Inability to be contacted by phone (via calls and/or text messaging) or email
   7. Any condition in the opinion of the physician that puts the participant at risk by participating in the study (e.g., serious respiratory illness requiring antibiotics or steroids or severe fever at the time of the study visit).
   8. Institutionalization