Routine blood work showed hgb 16.3 hct 48% rbc 5.48 all other values normal. healthy other than asthma. had mild covid dec 2021 was fully vaccinated and boosted. asthma slightly uncontrolled since covid. could this be the cause of the high values?

There are two possible explanation for mildly high Hb/Hct: the commonest cause is low volume at the time of blood test done and this is called hemoconcentration; if there is no other evidence of low volume, e.g. relatively high calcium, high albumin with serum sodium above 142, the mild & chronic hypoxemia, PO2 less than 80 by ABGs, due to chronic pulmonary condition is the cause of high Hb & Hct.