To do what? Repost your question with a few details.
In terms of oxygen saturations, arterial blood should be around 97-100% and venous return should be at approximately 75%. These figures are only appropriate for altitudes close to sea level.
the oxygen level decreases
Because due to the over pollution and cutting down the tree's level of Oxygen is decreasing .The level of Nitrogen always remains constant in the atmosphere . The level of Nitrogen doesn't' depend on the level of the Oxygen level.
The oxygen level remains about the same, but the density of the air is reduced.
Hypoxia
A normal blood oxygen level should be 90 or above (90-99). Any level below 89 qualifies you for oxygen. 74 is low and it means your brain and body are not getting enough oxygen. You should be evaluated by a pulmonologist and you should be on oxygen.
It should be 0.
If it is your oxygen level how old are you? and IRS ok its not perfect but you should be fine if it doesn't go back up to 100 go see your doctor.
In terms of oxygen saturations, arterial blood should be around 97-100% and venous return should be at approximately 75%. These figures are only appropriate for altitudes close to sea level.
Oxygen levels should be 98% or higher. Find professional help at a hospital. Right now!
About 98% is normal, no matter what a person's age is.
the oxygen level decreases
The oxygen level for an infant can be low if they are having breathing problems. They should be checked by a doctor as soon as possible.
PaO2 (partial pressure of oxygen) levels greater than 80 mm Hg should be avoided.
Oxygen's highest level is 100%. Oxygen's lowest level would be 20%.
If you refer to the blood oxygen level in humans, yes, that is a good level. In that context it is given as a percentage and in the human blood where it goes from 90 to 98 normally in a healthy person
Oxygen level should be in the upper 90's.... My son is on a machine so we can watch it regularly and the alarm goes off if he dips to 90.