Overnight Oximetry is a test that measures your heart rate and the amount of oxygen in your blood.When this is done overnight, a continuous measurement can be graphed. The graph helps see if you have enough oxygen in your body when you sleep. The machine records the information and the respiratory therapist prints it out in the morning for the doctor to review.This is completed Overnight in your own home, and is dropped back the next day to download the data and get the results. 

Doctors often like to monitor blood oxygen levels to see if you have enough oxygen at night.

The results help the assessment and treatment of your medical condition.