When the world woke up to COVID-19, the pandemic that has stalled our lives and thrown normalcy out of gear for the last few months, the widely reported symptoms were quite common in nature. It was often indicated that mild symptoms would mimic the regular flu, cold and cough and in serious cases, it could escalate into pneumonia, breathlessness.
Even as it started spreading across the globe, medical experts started witnessing a wide range of symptoms from diarrhea, loss of smell, taste, formation of clots in the tiny blood vessels. Despite frequent handwashing, staying indoors, maintaining social distancing, there seems to be no respite from this severely contagious infection. 
The latest to join the long list of COVID-19 symptoms is ‘happy hypoxia’ which means very low levels of oxygen in the blood, leaving medical professionals across the world baffled. Also Read: COVID-19: The Loss Of A Sense Of Smell, Taste Is Now A Symptom Of Coronavirus Infection
Read on, to gain further insight into what this peculiar occurrence means and the possible scientific reasons behind it.
So What Exactly Is Happy Hypoxia?
Hypoxia refers to very low oxygen levels in the blood. The normal oxygen saturation in the bloodstream of a healthy person is above 95%, but COVID-19 patients display dangerous declines of as less as 40%.
While hypoxia is a warning signal for imminent failure of vital body organs like the kidneys, brain, heart and is usually accompanied by prominent breathlessness, happy hypoxia does not prompt any such obvious external signs. As a result, in the initial stages of sickness, the COVID-19 patient, on the outside, appears to be alright and “happy”.
Why Do Oxygen Levels Decrease In Coronavirus-Infected Patients?
Coagulation, or more simply, widespread clotting, that takes place in the complex network of small blood vessels in the lungs, is considered, by a majority of researchers and medical experts, to be the primary cause of happy hypoxia.
The underlying factor behind this, is an inflammatory reaction in the body, most likely triggered by SARS-CoV-2 infection and the subsequent onset of COVID-19. This, in turn, instigates cellular protein reactions that form blood clots and prevent cells and tissues in the lungs from receiving adequate oxygen supply.
What Is A Pulse Oximeter Used For?
A pulse oximeter is a compact, portable gadget, that measures the oxygen amounts in the system. It is a non-invasive technique, that is used to rapidly obtain readings of blood oxygen saturation and also heart rate.
It is clipped firmly on to the fingertip and painlessly analyses two wavelengths of light from blood flowing through that region - one determining the oxygen levels in the bloodstream and the other gauging the pulse rate i.e. how fast the heartbeats. Also Read: Medical Devices: 5 Must-Have Health Monitors In Every Household
How Is This Device Effective In Tackling COVID-19?
The coronavirus disease is, first and foremost, a contagious illness that affects breathing and the upper respiratory tract, eventually damaging the lungs in advanced stages of the condition.
A pulse oximeter, is hence, a very useful instrument that can help detect falling blood oxygen concentrations in the early phase of COVID-19, much before the ailment manifests in more severe forms. This would assist in immediately isolating and providing prompt medical care for people afflicted by the virus, as well as significantly curb the spread of COVID-19 among the community.
Presently, the COVID-19 situation in India is intensifying, with more than 3 lakh people testing positive daily. As the country witnesses a rapidly escalating second peak of infections, many youngsters including teenagers and those in their 20s, 30s are also acquiring COVID-19. One alarming detail observed in these instances is how happy hypoxia develops in the younger population as well. While blood oxygen levels below 90 per cent are considered low, adolescents and youngsters with readings as low as 80 per cent or less do not exhibit any common symptoms of COVID-19 such as cough, fever and even have no challenges in breathing. However, this is a severe indication of malfunctioning of the lungs which requires immediate hospitalization and professional medical care. Certain prominent signs are displayed by not only young people but also the older population, who are either asymptomatic or have just mild symptoms of COVID-19 and still experiencing a state of happy hypoxia or decreased blood oxygen concentrations.
How To Identify Happy Hypoxia In People Who Are Asymptomatic Or Have Only Mild Symptoms Of COVID-19?
Even while portraying only minor symptoms of COVID-19, such as cough, sore throat, fever, headaches, without any perceivable breathing difficulty, it is advised to continuously measure blood oxygen levels using a pulse oximeter. Also, the colour of the lips changes from the natural shade to appear blue, while skin discolouration occurs from the original tone to a red/purple appearance. Persistent sweating even when not performing arduous exercise routines or in a hot surrounding is yet another red signal for low blood oxygen levels. Keeping an eye out for these warning signs of happy hypoxia ensures prompt treatment in a hospital setting, thereby restoring lung capacity and normal breathing in the affected individual and helping them recover from COVID-19.
