question: I have been diagnosed with noctural hypoxia but I exhibit signs of hypoxia during daytime also. Takes several days for symptoms to become noticeable. If use oxygen during day, no symptoms. Regular 6 min oxygen sat tests don t detect. Takes several days for oxygen levels to drop when no oxygen during day & several days for levels to rise when back on oxygen during day. I ve heard a test does exist that can definitely prove this exists. I found a dr who has heard of this but was subbing for primary at time & no one will tell me who she was or where located. 1st person in 2 yrs who knew it was true.