Causes of Low Blood Oxygen

In order to carry out various functions, our body requires a certain amount of oxygen circulating in our blood. The hemoglobin present in red blood cells binds atmospheric oxygen, and carries it to different parts of the body. The level of oxygen in our body is measured in terms of saturation of oxygen in the blood. When blood oxygen level goes below the normal level, i.e. below 95 percent, it can result in some complications in the overall health.

Low Blood Oxygen

The oxygen levels in blood can be measured by two means - first checking the arterial blood gas by resorting to a blood test, and second, by using a pulse oximeter (a device which is clipped on to the finger and to take oxygen readings in the blood). Blood oxygen levels ranging between 95-100 percent are considered ideal, as this is the amount of oxygen that is required by the body for proper functioning, while anything below 95 percent is something that needs prompt medical attention.

If the same depletes further, and reaches the 90 percent mark, it triggers a pathological condition referred to as hypoxemia. A life-threatening condition, hypoxemia is typically characterized by bluish discoloration of skin which is referred to as cyanosis. If it declines further and reaches 80 percent, the condition is referred to as severe hypoxemia.

What Causes Blood Oxygen Levels to Decline?

As we inhale oxygen, it travels all the way to our lungs, where it is absorbed by the alveoli. Eventually, it is dissolved in the blood stream, and transported to the various cells in the body. In case any disturbance occurs in this entire process, it disturbs the flow and results in fall in oxygen levels in the blood. As red blood cells are assigned the task of carrying oxygen to various parts of the body, anemia - an ailment typically characterized by deficiency of red blood cells, can also result in low blood oxygen. In fact, it is one of the most prominent causes of the same.

In several cases, low blood oxygen is attributed to some problems in functioning of lungs or heart - both of which have a crucial role to play in ensuring that adequate amount of oxygen is supplied to every region of our body. The health conditions associated with lungs include airway obstruction, ARDS (acute respiratory distress syndrome), chronic obstructive pulmonary disease (COPD), interstitial lung disease, emphysema, pneumonia, pneumothorax, pulmonary edema, etc. On the other hand, ailments associated with the heart include congenital heart disease, decreased cardiac output, etc.

The same can also be triggered as a result of activities which suppress breathing. At high altitude, the atmospheric concentration of oxygen is low, and therefore breathing becomes quite difficult. The resulting decrease in amount of oxygen inhale can, in turn, trigger hypoxemia. Similarly, narcotics abuse is yet another activity which can hamper the normal breathing pattern, and result in low blood oxygen. At the same time, major surgeries involving heart or lung, failure of the brain to drive breathing, and other such conditions are also known to bring down the amount of oxygen in your blood by a significant extent.

As low blood oxygen has the tendency to cause life-threatening complications, the underlying cause of this problem has to be identified and treated at the earliest. While a similar condition occurs when we are sleeping, that's perfectly normal as our body doesn't require much oxygen when we are sleeping - a state of rest. However, sleep apnea, a sleep disorder wherein breathing repeatedly stops and starts, does have the tendency to bring down the levels of oxygen in blood by a significant extent - and that is a reason to worry.