What are Normal Blood Oxygen Levels

Oxygen is probably the most important element that the human body takes in. Take into consideration the fact that the human body takes in 13 pints of air per minute into the body to take in oxygen. This is equivalent to about 7387.38 cubic centimeters (CC) per minute. The concentration of oxygen in the human body is also an equally important issue. Upfront, the normal blood oxygen level is about 95% to 100%, anything lesser than 85% to 90% means that you need to wear an oxygen mask. Smokers and continual alcohol consumers and the consumers of certain drugs usually have a concentration level which hovers around 90%. Here in this article, some facts regarding, the blood levels of oxygen have been mentioned.

Oxygen in the Human Blood

After we take in air into our lungs, the oxygen that is present in the air, enters the blood flow and gets trapped or deposited into the hemoglobin of the blood. Hemoglobin which is a crucial component of blood is principally a metalloprotein that is present in the red blood cells. Hemoglobin does the job of acting as a carrier or of a vessel for oxygen (O₂). When oxygen enters the blood flow and binds with hemoglobin the entire color of the blood gets changed from, dark bluish purple to red.

Concentration of blood in the human blood is referred to as oxygen saturation. It is sometimes also referred to as 'sats'. It is basically a unit that measures or depicts the saturation of oxygen in the blood and hemoglobin. In the human body, even saturation of oxygen in the blood flow is found. Lower levels of oxygen in the blood indicate that the saturation is not taking place properly. In simple words, the saturation process makes the blood appear like an aerated drink with hemoglobin being the carrier of the several O₂ molecules. A single hemoglobin molecule is like a small sphere, globular in shape and usually holds up to 4 molecules of oxygen. Now the unit, blood oxygen saturation principally refers to how much of that volume or capacity of the hemoglobin (and blood plasma), is getting bound to the oxygen molecules. This process takes place at the alveolar-capillary interface within the lungs. There are two prominent factors upon which the blood oxygen levels depend. One, the pressure of intake oxygen and two, the type and quality of hemoglobin that exits at the interface.

Hemoglobin Saturation Curve

In the aforementioned process, the binding of oxygen to hemoglobin is represented by a oxygen-hemoglobin dissociation curve . It also depicts a saturation levels of the blood that exits at the alveolar-capillary interface. As per the curve, the percentage of oxygen saturation goes on increasing towards the end of the breath. Hence the curve becomes upward projecting, in a manner than, towards the end of the breath, before you take your next breath, you will find that the last bonded portion of blood contains a maximum level of oxygen saturation (95% to 100%). This is possibly the best level of oxygen saturation for human blood and respiration, after all our body runs on aerobic metabolism.

Measurement of Normal Blood Oxygenation Levels

You will come across several percentages that have been marked and measured by a Pulse oximeter (measurement of actual blood saturation) or a Pulse oximetry test (measurement of oxygen in hemoglobin). This is basically the percentage of blood that has been saturated to the best possible limit. For the measurement of oxygen saturation, the Pulse oximetry or Pulse oximeter is attached to the patient's finger, upon which saturation can be measured properly.

As mentioned above, the normal level of blood oxygen fluctuate between 95% to 100%, for any normal adult. On the other hand, the normal blood oxygen levels in children is about 97%-98% and it then rises to about 100%. The oxygen saturation level also fluctuates as per the level of activity, for example, normal blood oxygen saturation during sleep is just below normal say 94% or so, as we are not doing any physical activity. During exercise the saturation almost touches 100% in a relatively short time period. In case of smokers the oxygen saturation level reach as low as 92%.

Some common disorders associated with oxygen intake and blood saturation include, Asphyxia that is the inability to breathe properly or Hypoxia, which is the inability of the saturated blood to reach one designated body organ properly. Another one is sleep apnea, which is actually a sleep disorder. In general, low levels of oxygen are known as hypoxemia, which show the symptom of cyanosis, which is the bluish discoloration of skin.

The tests for blood oxygen measurement, involve light based tests, and hence small kids do not have to worry about a needle while undergoing it. A simple test of blood oxygen often points out several problems in the human body.