‘Happy hypoxia’ is an unhappy & serious situation in COVID-19

‘Happy Hypoxia’ is one such condition that has been seen in a lot of patients with COVID-19.In happy hypoxia, a person’s oxygen levels are so low that they should be fainting or experiencing organ damage, but instead, they are seemingly well, until eventually they collapse. It is also called as ‘silent hypoxia’. COVID-19 is primarily a respiratory illness, and a severe case can reduce the amount of oxygen that the lungs can absorb. Blood oxygen levels have been found to be very low in some COVID-19 patients. 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”.


Blood oxygen levels below 90 percent are considered to be too low and oxygen therapy is needed for such patients. A person with low oxygen levels would have symptoms like shortness of breath and chest pain. However, in happy hypoxia, the person shows no such symptoms.

A pulse oximeter is used to detect blood oxygen levels in a COVID-19 patient.3 Also, in conditions like pneumonia, the reduction in blood oxygen saturation levels are accompanied by fluid collection and raised carbon dioxide levels in the lungs. The latter is what makes them unable to breathe properly instead of the low blood oxygen levels.

Hypoxemia, if left unchecked, leads to a condition called hypoxia (low tissue levels of oxygen), which can cause organ damage.1


Silent hypoxemia may disguise severity of clinical status in COVID-19 patients, and ultimately delay their seeking medical care. Patients admitted with COVID-19 may die without ever expressing the need for supplemental oxygen. Such hypoxemia can lead to the erroneous conclusion that patients are not in serious or critical condition, with the concomitant danger that they may quickly jump clinical evolution stages and develop ARDS, resulting in cardio respiratory arrest and death.5

It is urgent that the medical community be alert to silent hypoxemia in COVID-19, to assist physicians in their attempts to reduce the risk of sudden medical complications and death.


The following possible causes of happy hypoxia are observed in several studies.

1.  Difficulty in breathing is a symptom, not a sign:

Dyspnea (difficulty in breathing) is a symptom, only experienced by the patient, and not a sign that can be observed by others around the patient. A healthcare practitioner or a care giver cannot catch it until the patient shows signs like rapid breathing, fast heart beats or any other signs associated with the condition.

2. Carbon dioxide (CO2) tells the brain about hypoxia: 

Our brain senses carbon dioxide levels not oxygen levels in our blood. Minute changes in ventilation only occur after PaO2 (partial pressure of oxygen during exhalation) starts to drop below 60 mmHg. PaO2 is the measure of the pressure of oxygen in the blood in arteries. It tells you how well the oxygen is passing through the lungs and into the blood. Normal PaO2 levels are between 75-100 mmHg.3

In a study it was found that even a decrease of end-tidal PaO2 below 60 mmHg only increased dyspnea in half of the subjects even though all subjects should have experienced it. On the other hand, even a small increase in the pressure of carbon dioxide in arterial blood (PaCO2) would show large changes in ventilation. Even a reduction of blood carbon dioxide saturation level by 10mm Hg can cause respiratory issues that a person cannot tolerate for even a minute. But, severe hypoxia only leads to an increase in ventilation when the PaCO2 goes above 39 mmHg.

3. ACE2 receptors are present on brain cells that respond to hypoxia: Hypoxemia induces breathing difficulty through special chemical receptors called carotid bodies present in the brain. ACE2 receptors, the cell surface receptors that the COVID-19 causing virus uses to enter healthy cells, are present on carotid bodies too. So, it is a possibility that these receptors may play a role in dyspnea, however, more studies are needed to understand this.

4. Pulse oximeters are not as effective in critically-ill patients: Pulse oximeters are not as efficient in noting low oxygen saturation levels.

5. Fever may affect the way our body responds to hypoxia: Fever, a symptom of COVID-19, may have something to do with happy hypoxia. The carotid bodies in the brain only respond to PaO2 and not SaO2. However, the two could vary at different temperatures.2


In the latest study, the researchers at Loyola University took a poll from about 58 hospitals and healthcare practitioners to see if they have seen any patients with happy hypoxia. They found that 16 patients had PaO2 less than 60 mmHg but were not experiencing any discomfort. Seven of these patients had their PaCO2 levels above 39 mmHg (in the range between 41-49), which is the sign of silent hypoxia. However, the rest had PaCO2 levels below 39 mmHg. Since this level can blunt the effects of hypoxia on the brain, these patients were not considered to have happy hypoxia.
A lot of COVID-19 patients are either diabetic or old — two conditions that reduce the response of the respiratory system to hypoxia. It has been indicated that diabetics and people older than 65 years have a 50 percent reduced response to hypoxia. So the study suggested that such patients with COVID-19 may be more prone to silent hypoxia.

Furthermore, most people have around 300-600 percent difference in their respiratory drive (the response of their respiratory muscles to the respiratory centres in their brain). So, while one patient may quickly develop shortness of breath with higher blood carbon dioxide levels, another one may not.2


Over the last few weeks, many healthcare workers have observed a rather confusing pattern among some of the patients. They say that these patients start to show signs of recovery behave normally and then collapse rapidly without leaving scope for intervention. Some patients also show an unusual response to very low oxygen levels as they do not complain of breathlessness or discomfort. This – ‘happy hypoxia’ – is an uncharted territory for doctors too.2

Sudden collapse may have been occurring due to many other reasons for a person. ‘Happy hypoxia’ is possibly just one subset but this can’t be said conclusively. Other possible reasons are cytokine storms where the body observes a surge of toxins to fight the coronavirus – can also be seen as an immune system going overboard. The next is blood vessels getting clotted and blocked. Then there could be a septic shock and hypoxia.”

Symptoms of hypoxemia may be acute or chronic which mainly include:

Shortness of breath
Rapid breathing
Fast heart rate
Sensation of choking
Fluid retention at high altitudes
Changes in the color of skin from blue to cherry red
Severe symptoms seen with cerebral hypoxia may include:

Inability to communicate
The patients’ condition may enter into the emergency with blood oxygen levels as low as 50%, so low they should have been incoherent, even unconscious. Normal blood oxygen saturation is between 95% and 100%, and anything below 90% is considered abnormal.

In addition scans of these patients’ lungs showed signs of pneumonia so severe they should be in terrible pain as they gasp for their next breath. In case of asthma patients their X-ray’s looked awful, their oxygen was terrible, and yet they’re completely awake & alert. It can be noticed either shortness of breath or fatigue or something else. It’s terrible because by the time a person realizes they are having trouble taking a deep breath and reaches out for help, they are already dangerously sick. Some may ultimately require a ventilator as levels of carbon dioxide rise, fluid builds up in the air sacs and the lungs become stiff, leading to acute respiratory failure.

Stop smoking- Smoking can trigger the asthma symptoms leading to hypoxemia.
Deep breathing and coughing techniques- These techniques help patients effectively clear their airway while maintaining their oxygen levels.
Use of Bronchodilators- Medications such as bronchodilators effectively relax smooth muscles and open airways in certain disease processes such as COPD.
Oral suctioning- Patients with muscle disorders or those who have suffered a cerebral vascular accident (CVA) may have ineffective cough reflexes, which could lead to hypoxia. Oral suctioning given to these patients may help to prevent this condition.
Hypoxic training- Hypoxic training should be given to maintain good health.
Take medicines and use the rescue inhaler when needed to help prevent flares.
Stress can trigger many respiratory disorders leading to hypoxemia and should be avoided.
In Homoeopathy there are many medicines mentioned with Hypoxia situation in human. Some important medicines are Amon Carb., Aurum Met., Cactus Grand., Carbo Veg., Camphora, Ignatia Amara, Lachesis, Staphisagaria etc. In my practical experience I found timely medication is like a wonder to control the emergency situations. My one case of hypoxia due to Covid-19 was well responded within three hrs. without any oxygen support. The PaO2 was fallen to 85. Frequent diluted doses of CAMPHORA 1M shows the miraculous effect and the oxygen label raised up to 95 just in 45 minutes. I experienced the best of CAMPHORA effect on many Covid-19 positive cases.4
If any COVID-19 patients are experiencing hypoxemia, we must try homoeopathy with thorough confirmation of patients’ symptoms physical & mental as well & put him/her on homoeopathic medicine. My experience says that if we deal the case of COVID-19 sincerely, we may gate the good result. In many cases we saw that the patients are dying on ventilators and they are collapsing after behaving normally, we can consider to use homoeopathy & I am sure that we can save many more lives. In case of Hypoxia It can be said that my few patients are having low level of PaO2 (fallen to 82, 85) but with homoeopathy, it shows recovery & saw the patient become normal in reasonable time. I experienced that one case was in a condition to put on Oxygen but he prefer to taka homeopathy and waited for few minutes/hour and the result was good.


 1. [Last accessed on 2020 Jun 07]. 

3.    3.Pandey A. Covid-19: Naval Dockyard Manufactures Innovative Portable Multi-Feed Oxygen Manifold. Available from: manufactures-innovative-portable-multi-feed-oxygen-manifold-1661553-2020-03-31. [Last accessed on 2020 Jun 07].  

4.Mac Repertory & reference work by Synergy  

5. 5.Anoop UR, Verma K. Happy hypoxemia in COVID-19. A neural hypothesis. ACS Chem Neurosci. 2020 Jul 1;11(13):1865–7.

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