I'm dealing with GERD issues and sometimes it feels like my breath gets stuck. To keep an eye on things, I've started using a pulse oximeter daily to check my oxygen level. But here's the thing, I'm getting some really weird readings. It starts at 98 or 99, but then after 20 to 30 seconds, it suddenly drops to numbers like 79, 89, or even 60, before going back up to 98 or 94. These abnormal readings only last for about 3 to 4 seconds. Other than this sensation like somethings stuck, I'm generally active and dont have other major issues. Should I be concerned about these fluctuating numbers, or is this normal with a pulse oximeter? What's going on?

Spirometry and pulmonary function tests is advised to the patient.