Use of fenoTRACK Device for Monitoring Changes of Fractional Exhaled Nitric Oxide (FeNO) in Uncontrolled Asthma Subjects and Controlled Asthma Subjects

This study tests a new home device called fenoTRACK, which measures exhaled nitric oxide (a marker of airway inflammation) in people with asthma. Researchers want to see if the device accurately tracks changes in asthma control over time in both well-controlled and poorly controlled asthma. **You may be eligible if...** - You (or your child) are 5 years old or older with a diagnosis of asthma - For the uncontrolled asthma group: you have symptoms on at least 2 days per week (coughing, wheezing, shortness of breath, etc.) and elevated exhaled nitric oxide levels - For the controlled asthma group: you have had asthma for at least 180 days and it is well-managed - You are willing and able to complete all study procedures **You may NOT be eligible if...** - You do not have an asthma diagnosis - You do not meet the symptom or nitric oxide threshold for the uncontrolled group - You are unable or unwilling to complete the study visits and procedures Talk to your doctor to see if this trial is right for you.