From an early age, we all learned that we breathe in oxygen and breathe out carbon dioxide. This was the introduction to the biology of human life and is for many people a fundamental lesson we have never forgotten.

While the biological aspects of human life are complicated and cannot be summarized in a single statement, the oxygen influence can never be under looked. This is because humans, similar to all other mammals, along with most other animal species, require oxygen to survive. As such, despite forming 21% of the earth’s atmosphere, oxygen is one of the most used gases as most living organisms require it.

As humans, our bodies process three things, namely; food, liquid, and oxygen that are necessary to stay alive. However, while our bodies can store up food and liquid, they cannot store oxygen. As a result, we have a constant demand for oxygen for as long as we are alive.

Even for the food and liquid demanded by the body, the only way it becomes useful is through oxidation. Primarily, oxidation is the process by which food and liquid are chemically changed into energy by making use of the oxygen that we breathe.

The by-products of the complex enzymatic processes are carbon dioxide and water that are eliminated from the body when we breathe out. So why do we need oxygen to breathe?

Overly, there are lots of other reasons why the human body requires sufficient oxygen supply to breathe and, therefore, survive, and these include:

  1. Cellular respiration

The human body cells need oxygen for aerobic cellular respiration, which is the primary process by which stored energy is converted into a usable form. The first stage of this type of respiration is known as glycolysis, whereby glucose in the body gets converted to pyruvate, which is a carbon-based molecule.

While this stage does not require oxygen for cellular respiration to occur beyond this stage, our cells must use oxygen. Lack of oxygen in the body will result in the broken-down pyruvate undergoing fermentation to produce lactic acid.

  1. Electron transport chain

There is constant movement in the electron transport chain. This chain is vital for carrying electrons to the cells where they are used for adenosine triphosphate (ATP) production. This process cannot be possible without oxygen as there is a need for the used electrons to be eliminated from the body.

The ability of the electrons to combine with oxygen and hydrogen to form water makes this a flawless process. However, if oxygen would not be available during this step, there would be a buildup of electrons. Consequently, the electronic transport chain would be clogged, and ATP production would stop.

  1. Support mental performance

Besides being required to create energy for our bodies, oxygen is essential for mental performance. Different from muscles in the body that can store energy, the brain lacks the capabilities to do this. As such, it needs a steady flow of oxygen and nutrients to function normally, and deprivations will lead to severe implications.

It is important to note that while the brain comprises 2% of the human body mass, it uses up to 20% of the oxygen the body needs.

The functions of oxygen in the human body

Having the right oxygen levels in the body is essential as lots of body functions depend on this aspect. Among the benefits associated with the right oxygen levels are:



  1. It helps in the digestion of food
  2. Strengthens our immune system
  3. Removes harmful bacteria, viruses, and parasites from the body
  4. It is required for the manufacture of hormones and proteins
  5. Transports other gases across the cell membranes
  6. Metabolizes fats and carbohydrates
  7. Keeps the heart pumping for proper blood circulation
  8. Neutralizes acids such as lactate acid that builds up in the body
  9. Boosts chemical pathways in the body
  10. Improves wound healing as it stimulates the generation of new capillaries around the wound
  11. Removes free radicals and toxins from the body
  12. Fuels the body muscles

The critical role of oxygen in the human body is primarily supported by the fact that breathing is an involuntary action. This means that we never have to struggle to acquire oxygen as each second we breathe without having to be conscious about it.

However, this does not mean that at all times, we will be able to naturally have the required oxygen levels in the body. Fortunately, our bodies closely monitor this, and when the levels start to drop, there will be signs that you need extra oxygen.

Among the signs that could show you have low oxygen levels in the blood are:

  • Shortness of breath and dizziness. While it is possible for the body to burn fuel with low oxygen levels, it will not produce the energy for normal body functions. This is often manifested by having shortness of breath and suddenly getting dizzy.
  • Headache and confusion. Without the right oxygen levels, the brain instantly starts sending signals, and this results in getting a pounding head that is paired with confusion. The confusion is because you are not able to concentrate as your body gets into a panic mode.
  • Pounding heart. As the oxygen level decreases, the heart will start working harder as it strives to support oxygen circulation in the body. As such, you will have a racing heart that is accompanied by other anxiety symptoms.
  • Chest pain and restlessness. This is due to the heart overworking and the body wanting to find sufficient oxygen to support all functions.

Possible causes of low oxygen supply to the body

Low blood oxygen levels are caused when:

Most people who experience low blood oxygen levels have medical conditions that affect their abilities to take in oxygen. These conditions include:

  1. Chronic obstructive pulmonary disease
  2. Cystic fibrosis
  3. Acute lung failure
  4. Severe sleep apnea
  5. Severe infections
  6. Decompression sickness
  7. Pneumonia
  8. Heart diseases
  9. Lung diseases

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