I'm a 28-year-old woman who works out regularly. My mom has a pulse oximeter at home and I decided to use it just for fun. When I was resting, my blood oxygen level was 99, but after a short run on the treadmill it went down to 86. My heart rate was only around 130. Usually, I work out a lot more intensely than I did during this test. I'm worried that I might unknowingly be harming my body. Do you think I should get this checked? If so, what kind of doctor would be best for evaluating this situation?

It's understandable to be concerned, but a drop in oxygen saturation during exercise, especially at high intensity, can happen, particularly if you're pushing your limits. I recommend seeing a pulmonologist or a cardiologist to evaluate your lung and heart function. They can conduct tests like a stress test or pulmonary function test to assess your oxygen levels and overall health during exertion.