What Is Hypoxia?
Hypoxia, in simple words, can be defined as decreased oxygen levels in the tissues. This deficit in oxygen levels in tissue is not enough to carry out the functions of the body. Hypoxia is often confused with another similar yet different term, hypoxemia. Hypoxemia refers to decreased oxygen levels in the blood. Hypoxemia often leads to hypoxia which is why hypoxia is frequently used to describe both conditions. Low oxygen levels in the tissues and blood can be dangerous and cause permanent damage.
What Is Happy Hypoxia?
Happy hypoxia was prevalent during the second wave of the COVID-19 (coronavirus disease) pandemic. The medical term for this ailment is "silent hypoxia," although some doctors refer to it informally as "happy hypoxia." Several COVID patients during the second wave had critically low blood oxygen levels, yet they showed no signs and symptoms of dyspnea (breathlessness). Healthy individuals typically have blood oxygen saturation levels above 95 %, while COVID-19 patients show severe decreases of as low as 40 %. Many medical specialists worldwide are perplexed by the condition because COVID-positive patients should actually be fainting or undergoing organ damage due to abnormally low blood oxygen levels. Still, instead, they appear to be normal. This is why the condition is called "happy" or "silent" hypoxia. These patients are at higher risk because they do not have dyspnea despite having very low oxygen saturation levels.
What Causes Happy Hypoxia?
The prevalence of happy hypoxia in COVID-positive patients has been seen in many cases; however, the mechanism underlying this condition is still not fully understood. Most medical professionals believe that extensive clotting, or coagulation, that occurs in the intricate system of tiny blood vessels in the lungs is the main cause of happy hypoxia.
What Causes Lack of Symptoms in Happy Hypoxia?
According to studies, the following may account for the absence of dyspnea and other symptoms in silent hypoxic COVID-19 patients:
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Increased Levels of Carbon Dioxide: The changes in carbon dioxide level initiate a hypoxia threshold, causing an absence of lung damage symptoms and dyspnea.
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Impact of the Virus on the Brain: The coronavirus may impact the brain and the nervous system leading to alterations in the process that regulates respiration.
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Impact of the Virus on the Blood Vessels: The virus may impact blood vessels and cause a lack of hypoxic blood vessel constriction.
What Are the Symptoms of Happy Hypoxia?
Although patients with silent or happy hypoxia may not present with any symptoms of their alarmingly low oxygen levels, they may present with some of the following symptoms:
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Cough.
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Wheezing.
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Sweating.
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Fever.
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Increased or decreased heart rate.
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Bluish discolorations of the lips.
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Discoloration of the skin.
How Can Happy Hypoxia Be Identified in Mild COVID Symptoms?
Apart from the general symptoms of COVID-19 infections like fever, loss of taste, loss of smell, diarrhea, headache, etc., a patient with happy hypoxia may exhibit the following symptoms:
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Discoloration of the skin.
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Bluish discoloration of the lips.
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Profuse sweating even without doing any tedious chores.
How Can Happy Hypoxia Be Diagnosed?
Silent hypoxia can be diagnosed with the help of the following tests and devices:
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Pulse Oximeter: A pulse oximeter is a commonly used and conventional medical device used to noninvasively measure oxygen saturation levels, heart rate, and respiratory function. It is a quick and easy method of checking blood saturation levels, and it can be done by the patient as well. However, it is crucial to ensure that the pulse oximeter is accurate, specifically in cases when the patient's oxygen saturation drops below 90 %. To diagnose happy hypoxia, continuous pulse oximeter monitoring of arterial oxygenation is necessary. The device, which is placed over the fingertip, analyzes two light wavelengths from blood flowing through that area, one of which measures the blood's oxygen levels and the other measures the pulse rate.
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Blood Gas Analysis: A blood sample is collected from an artery and subjected to arterial blood gas analysis to determine the levels of various gasses in the blood. When blood samples are properly evaluated using this approach, a vast spectrum of standard parameters can be obtained, including partial pressures of carbon dioxide and oxygen. These data can be used to analyze acidosis, alkalosis, and silent hypoxia. Patients with happy hypoxia usually have increased partial pressure of carbon dioxide.
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6-Minute Walking Test: Happy hypoxia in COVID-positive patients may also be detected with the help of a 6-minute walking test. During this test, the oxygen saturation is measured after 6 minutes of walking. According to reports, patients with COVID-19 had considerably lower oxygen saturation levels than the control group.
When to Seek Medical Help?
Immediate medical help should be sought in the following cases:
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The oxygen level falls below 94 % when checked on the pulse oximeter.
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Shortness of breath while doing minimal physical activity.
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Having significant, unexpected shortness of breath that makes it difficult to carry out daily activities
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Severe difficulty in breathing, even at rest or while sleeping.
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It is necessary to seek medical help while experiencing a feeling of choking.
Conclusion:
Hypoxia is generally a warning indication for impending organ failure in the body, such as lungs, kidneys, brain, or heart failure, and is frequently accompanied by severe dyspnea; happy hypoxia does not cause any prominently visible symptoms associated with serious health conditions. The COVID-19 patients consequently present as healthy and "happy" outside during the early stages of the infection, which delays the diagnosis and worsens the prognosis.
