I have mild breathing issues during winters, which affects my sleep and I used to wake up with a headache. The fingertip SpO2 meter helps quantify the problem, so it was a good buy. According to my readings, headaches were bad when my readings were 92 or lower. Also helped when my son was having bouts of bronchiolitis when he was younger.

It's only about $50 and batteries last long, so I'd totally recommend it if you have breathing ailments. Maybe even otherwise.

Oximeter. They're cheap, you can grab one on Amazon for $40. My friend who mailed me the medicine supplies (who is married to a doctor) insisted I have it and that I measure it regularly.

> Is this something that people with rescue inhalers also typically have?

I'm not sure. I usually get a rescue inhaler prescribed roughly once a year to help get over a cold. I have light asthma and bad allergies. The breathing here in Denver is definitely more challenging in general as well.

not who you are asking but search for a “fingertip oximeter” to measure your blood oxygen level.