Oxygen saturation refers to the level of oxygen carried by red blood cells through the arteries and delivered to internal organs. As red blood cells travel through the lungs, they are saturated with oxygen. A low saturation level could indicate a respiratory illness or other medical condition.
Oxygen saturation is measured to determine the severity of an illness and is often the determining factor for treatment. If red blood cells are not adequately transporting oxygen throughout the body, the saturation level falls.
Oxygen saturation is measured by pulse oximetry, which uses a sensor of two light sources that hemoglobin absorbs then transmits through the body's tissues. A photodetector picks up the amount of light and converts it to a digital number, which is known as the oxygen saturation level or value.
Oxygen saturation level in healthy patients is considered normal between 97 percent and 99 percent. Patients who have normal hemoglobin levels can have a saturation level of 95. When the amount of oxygen in the blood is reduced, a condition known as hypoxemia results, and treatment is then required. In severe cases of hypoxemia, the patient exhibit a blue tint on his lips, gums, nail beds and around the mouth and eyes. This condition is called cyanosis.
Monitoring oxygen saturation requires a noninvasive monitor that is placed on a finger or toe. Known as pulse oximetry, the probe picks up a measurement of oxygen saturation through the infrared light that passes through tissue.
Oxygen saturation can also be measured through arterial blood gas. Unlike other blood tests, this test takes blood from an artery and measures the amount of oxygen. Arteries carry oxygenated blood away from the heart. A physician might order this test in conjunction with pulse oximetry.
When oxygen saturation levels dip below the normal range, treatment usually involves oxygen therapy. A high concentration of oxygen is delivered by a ventilator through a mask or nasal cannulae (tubes).
Symptoms of Low Blood Oxygen
Low blood oxygen, also known as hypoxemia, is a condition where the oxygen level in your arterial blood drops below a normal...
Normal Oxygen Level of a Person
Since every person breathes, it might be assumed that all people have the same level of oxygen within their bodies. However, oxygen...
What Are Normal Blood Oxygen Levels?
Blood oxygen levels tell your doctor how much oxygen is traveling through your blood to the cells in your body. Without enough...
Normal Oxygen Saturation Range for People
Oxygen saturation is a noninvasive way to measure how much oxygen is moving through the bloodstream. This test is performed by a...
Normal Oxygen Saturation Levels in Children
An oxygen saturation level reflects the amount of oxygen-rich blood passing through the bloodstream. Defined by the Department of Pediatrics at the...
What Are the Causes of Decreased Saturation of Oxygen?
The body needs oxygen to function properly and stay alive. Oxygen is delivered to the tissues and organs in the body by...
What Occurs When Oxygen Saturation Levels Are High?
Oxygen can be a double-edged sword. On one hand, we need oxygen to survive. On the other hand, when exposed to higher...
What Is Iron Saturation?
Iron is a mineral that is essential for hemoglobin (a protein in the red blood cells) to properly carry oxygen. Seventy percent...