Hi doctor, my brother is covid recovered person. He had completed 40 day after covid. His ct score was 12. His recent xray( after 30 day of first ct scan) ...is completely normal. He measure his oxygen.day and night. His oxygen goes till 94-96 when he incline position on sofa or lying down on bed and goes to 97-98 when he sits staight and measure. Is this normally behaviour of spo2?? he measure his sp02 after 10 mim treadmill also which comes around 97-98..He get tense when he see lower score and get normal when it comes 98 after sitting position. Please guide.