Understanding Normal Blood Oxygen Levels
Oxygen is critical to our well-being. Without it, our bodies would be unable to synthesize food and many of our muscle operations would become impossible. Not only must oxygen be present in our blood but it should be present in very specific quantities. This is what we call blood oxygen levels and in normal circumstances, these levels are carefully regulated by our bodies to ensure that there is a very precise balance.
However, sometimes we have low blood oxygen levels as a result of various ailments. When this happens, it is important to understand the situation as quickly as possible and take remedial measures.
Causes of Low Blood Oxygen Levels
In a healthy human being, normal blood oxygen levels fall between 80 and 100 ml of Mercury (this is abbreviated as mm Hg). For most healthy people, the range is usually 95-100%. However, when people have respiratory issues such as lung disease or when suffering from sleep apnea, blood oxygen levels may fall to levels that can cause damage to critical organs. This state of low oxygen levels is called hypoxemia and is normally diagnosed when a patient’s mm Hg levels fall below 80.
Symptoms of Low Blood Oxygen Level
When your blood oxygen levels fall, patients may experience the following:
- Difficulties in breathing
- Chest pains
- Faster heartbeat
If there is no intervention, the problem develops into what is known as Cyanosis. This is a medical emergency characterized by discoloration of nail beds (they turn blue). The same effect is observed in your mucus membranes as well as on your skin. Without rapid treatment, the condition may develop into respiratory failure which can be fatal.
Since these levels keep changing over days or even hours, patients suffering from any condition that affects their blood oxygen levels are normally asked to monitor it. There are also laboratory tests to measure blood oxygen levels. Let us have a look at some of these:
Arterial Blood Test
This is a laboratory test and involves doctors drawing blood out of an artery and not a vein. This is because arteries carry blood from the heart to the rest of the body. This is the blood that has the highest concentration of oxygen and so your doctor can get a pretty good idea of your blood oxygen levels. While this test is very accurate, it is also invasive and can not be done without a trained healthcare professional.
A pulse oximeter is a device that uses infrared rays to determine the amount of oxygen in your blood. These infrared rays are transmitted into blood vessels in your finger, earlobe, or toe. Oxygen in the blood reflects these rays and the machine is then able to determine how much oxygen your blood has. Doctors use these devices to get a quick reading first. They may then follow up with a laboratory test if they feel the situation warrants further investigation.
Since these devices are non-invasive, they are also available for sale for home use. There are even pulse oximeters for children! Typically, patients will be advised by their doctors to purchase them in order to keep track of their oxygen levels.