Updated: Aug 3, 2020
An important issue that people nowadays suffering to. A pulse oximeter is a device that sends a beam of light through a finger (has been discussed in detail in my previous article https://munidoktor.blogspot.com/2020/07/a-pulse-oximeter-and-basic-principal-on.html
Since we know that oxygenated blood is not the same color as de-oxygenated blood the amount of light that is transmitted is proportional to the concentration of oxygen in the blood. The machine is calibrated to give you a number that tells you how much of the blood is oxygenated. The pulse oximeter will not tell you what is wrong with you. It will only tell you if your breathing is okay. There is a big difference in having a cough and your oxygen saturation is in the 90’s and having the same cough and your saturation is in the 70’s. If you are in the 90’s you are breathing adequately. You can afford to lose some lung function and still be okay. Once you descend into the 70’s, you are at the edge of the precipice. Even a slight decrease in lung function will be very fatal very quickly.
So pulse oximeter will not tell you if you specifically have the covid-19 and any lungs or hearts and a few other conditions canbe cause of a drop in the saturation levels in the blood. But a lot of covid 19 patients seem to have a silent type of pneumonia where the oxygen levels fall quite a bit before the patents start observing troubling symptoms.
So for people, whole saturations have been normal to observe a fall in saturation one of the likely causes in this present-day pandemic could be caused by the Covid-19. You should visit your doctor and assess the need to get tested. It might lead to an early diagnosis before you develop severe symptoms.