Have you ever experienced a sudden and unexplained feeling of lethargy and shortness of breath? Do you have trouble focusing or remembering things? You may be suffering from Hypoxemia (low oxygen saturation in the blood). From shortness of breath to organ failure, the effects of low blood oxygen can be devastating.

This article will explain signs of hypoxemia, 5 potential risks and consequences of low blood oxygen saturation and who is at the risk of developing hypoxemia.

Normally, oxygen levels in your blood range from 94% to 100%. [1] This indicates that your body's red blood cells are adequately stocked with oxygen to meet the needs of all of your organs and tissues.

Normal blood oxygen levels ensure that these organs can function smoothly without any hindrance or risk of damage.

Hypoxemia means the oxygen level in the blood drops below 88%.

Hypoxemia in terms of partial pressure of Oxygen

Normal Arterial Blood Gases (ABG) test values range from 75 to 100 mm Hg. If the values drop below 75 mm Hg, it indicates hypoxemia. [2] 

The most common hypoxemia signs include:

●Shortness of breath

●Rapid heartbeat

●Chest pain

●Headache

●Dizziness

●Confusion

●Weakness

●Restlessness

●Cyanosis (in severe cases) 

Here are the five major consequences of low blood oxygen:

The most noticeable signs of low blood oxygen levels are fatigue and difficulty breathing.

If your body isn't getting enough oxygen, even the most basic activities, like walking or climbing stairs, become exhausting tasks.

People with chronic fatigue frequently struggle to get through their days because they are too exhausted to function normally. They may also struggle to maintain attention throughout the day.

Low blood oxygen can have severe consequences on cognitive function. [3] Our brain requires a significant amount of oxygen to operate correctly, and when deprived of it, the resulting damage can be permanent.

●Impaired memory: The hippocampus, responsible for creating new memories, is particularly vulnerable to hypoxemia (low blood oxygen levels). People with chronic hypoxemia may experience difficulties remembering recent events or retaining new information.

●Impaired decision-making: Even mild hypoxemia has been shown to impair higher-level thinking processes, such as judgment and problem-solving abilities.

A 2018 study published in the Journal of Alzheimer's Disease found that individuals with sleep apnea were three times more likely to develop Alzheimer's disease than those without it. [4]

It is a pathological condition in which the blood pressure in the pulmonary arteries is elevated, resulting in increased resistance to blood flow and impaired cardiac function. In this way, the circulation of oxygenated blood throughout the body is impeded.

According to a study published in the American journal of respiratory and critical care medicine, chronic hypoxemia (CH) causes the walls of your pulmonary arteries to become thickened and stiff, which puts more pressure on your heart. [5]

Symptoms of PAH include:

●Weakness

●Difficulty in breathing

●Chest discomfort

●Dizziness

If left untreated, pulmonary hypertension can cause serious damage to your heart and lungs over time. 

The immune system relies on a steady supply of oxygen to function properly. Without enough oxygen, white blood cells are unable to effectively combat dangerous microorganisms that may lead to respiratory disorders like pneumonia and bronchitis.

In addition to weakening the immune system, low blood oxygen can also damage other organs that play a key role in immunity. For example, if there is not enough oxygen reaching the liver or spleen, these organs may be unable to produce enough white blood cells for proper immune function.

Reduced blood supply to important organs increases the risk of organ damage. Cells inside an organ may begin to die if it doesn't get enough oxygen-rich blood. Over time, this can cause permanent damage and even lead to organ failure. The heart, brain, kidneys, lungs, liver, and other organs may all suffer from chronic hypoxemia.

●Heart: When there isn't enough oxygen available, the heart has to work harder, which puts additional strain on the cardiovascular system.

●Brain: The brain requires a constant supply of oxygen for our cognitive functions, such as memory retention and concentration skills, to remain intact.

●Kidneys: Decreased kidney function may occur due to insufficient O2 reaching the filtering systems found within our kidneys. If left untreated it can lead to chronic renal failure.

Certain groups may be more susceptible to experiencing low oxygen levels in their blood.

●Smokers

●Individuals with lungs diseases such as emphysema, asthma, COPD

●People who live at high altitudes

●Individuals with sleep apnea or other breathing disorders during sleep

●Patients undergoing surgery or being placed under general anesthesia for procedures 

Low blood oxygen can lead to various potential risks and consequences. From fatigue to cognitive impairment, pulmonary hypertension, low immunity, and less blood flow to vital organs, serious conditions could significantly affect your quality of life. Adopt a healthy lifestyle to prevent hypoxemia. In conclusion, being aware of the risks of low blood oxygen and taking steps towards prevention will help you maintain optimal health and well-being.

References

1.Oxygen by WHO. Available from: https://www.who.int/news-room/questions-and-answers/item/oxygen

2.Castro D, Patil SM, Keenaghan M. Arterial Blood Gas. [Updated 2022 Sep 12]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK536919/

3.García-Grimshaw, M., Chirino-Pérez, A., Flores-Silva, F. D., Valdés-Ferrer, S. I., Vargas-Martínez, M. L. Á., Jiménez-Ávila, A. I., Chávez-Martínez, O. A., Ramos-Galicia, E. M., Marché-Fernández, O. A., Ramírez-Carrillo, M. F., Grajeda-González, S. L., Ramírez-Jiménez, M. E., Chávez-Manzanera, E. A., Tusié-Luna, M. T., Ochoa-Guzmán, A., Cantú-Brito, C., Fernandez-Ruiz, J., & Chiquete, E. (2022). Critical role of acute hypoxemia on the cognitive impairment after severe COVID-19 pneumonia: a multivariate causality model analysis. Neurological sciences : official journal of the Italian Neurological Society and the Italian Society of Clinical Neurophysiology, 43(4), 2217–2229.

4.Andrade, A. G., Bubu, O. M., Varga, A. W., & Osorio, R. S. (2018). The Relationship between Obstructive Sleep Apnea and Alzheimer's Disease. Journal of Alzheimer's disease : JAD, 64(s1), S255–S270. 

5.Ball, M. K., Waypa, G. B., Mungai, P. T., Nielsen, J. M., Czech, L., Dudley, V. J., Beussink, L., Dettman, R. W., Berkelhamer, S. K., Steinhorn, R. H., Shah, S. J., & Schumacker, P. T. (2014). Regulation of hypoxia-induced pulmonary hypertension by vascular smooth muscle hypoxia-inducible factor-1α. American journal of respiratory and critical care medicine, 189(3), 314–324.