Blood oxygen saturation, also known as SpO2, refers to the percentage of oxygen that is bound to hemoglobin molecules in the blood. It is an important measure of how well oxygen is being delivered to the body's tissues and organs. Our bodies closely regulate our blood oxygen levels; maintaining the right balance of oxygen-saturated blood is essential for good health.
Currently, there are two types of tests to measure blood oxygen levels: the arterial blood gas (ABG) test and the pulse oximeter. ABG is highly accurate, but comes at the cost of being invasive, as it involves drawing blood from an artery. The test measures oxygen levels, other gasses in the blood, and pH levels. The pulse oximeter, on the other hand, is noninvasive, and it estimates blood oxygen levels by sending infrared light into capillaries in the finger, toe, or earlobe. The test is easy to perform and widely used by doctors for quick readings; however factors such as dark nail polish and cold extremities can affect the results, and the test is slightly less accurate than the ABG, with a 2% error window. Yet people with chronic health conditions such as asthma, heart disease, and COPD may need to monitor their blood oxygen levels regularly, making a fast and noninvasive test preferable. Apple Watch can also monitor blood oxygen levels, but it's not as accurate as the ABG test or pulse oximeter. It's essential to talk to a doctor before using a home device to understand how to interpret the results.
A pulse oximeter works by emitting a beam of light through the skin and detecting the amount of light that is absorbed by the oxygenated and deoxygenated hemoglobin in the blood. It is commonly placed on the finger, but can also be placed on other parts of the body, such as the earlobe or toe. The amount of light absorbed depends on the concentration of the light-absorbing substance, the length of the light path in the absorbing substance, and the oxyhemoglobin and deoxyhemoglobin absorb red and infrared light differently. Pulse oximetry uses light to work out oxygen saturation. Light is emitted from light sources which go across the pulse oximeter probe and reach the light detector.
People with healthy lungs should have a blood oxygen level of 80-100 mm Hg, or 95-100% when measured with a pulse oximeter. For people with lung diseases, a doctor should determine the optimal levels. Low blood oxygen level is called hypoxemia and can lead to complications in body tissue and organs. It is important to know what’s normal for you, especially if you have a chronic lung condition. Other physical symptoms of low blood oxygen level include shortness of breath, chest pain, confusion, headache, and rapid heartbeat.
Here are some tips and techniques for maintaining a healthy and normal blood oxygen level. You can try ‘Pursed lip breathing’ where you inhale through your nose for 2 seconds and then exhale through pursed lips for the same amount of time. You can also try ‘Belly breathing’; this is when you start by taking a few deep breaths through your nose and use your hand to feel the air swelling up your belly. After that, exhale through your lips for 2 or 3 times as long as you did while you were breathing in. Furthermore, you may get more oxygen by going for a stroll outside, letting fresh air into your home, or adding houseplants. Additionally, you may alter your way of life by giving up smoking, avoiding secondhand smoke, engaging in regular exercise, and maintaining a healthy diet.