I have had asthma since I was 16, so I'm very familiar with using a fingertip pulse oximeter. This is the device they use to find out the amount of oxygen in your blood. They use this to monitor when your at an appropriate level to leave the hospital. This fingertip pulse oximeter is just like the ones they use in the hospital. It is digital and easy to read. It is padded and very comfortable to wear on your finger. It not only gives you your blood oxygen level in minutes but also your pulse rate. You can see your results in numbers as well as wave forms or bar graph. This will give you a visual indication of irregular or weak heart beat. There is an alarm that will sound if you have an abnormal SpO2 level or pulse rate. The device automatically powers off after 10 seconds of inactivity, so you don't have to worry about the battery going dead. It comes with a nice heavy duty little carrying case so you can monitor on the go. It is great to have this tool at home, so you can monitor your levels yourself. If you'd like to try one of these handy tools, you can find it Here.