Does the brain need oxygen?

In this post we are going to answer the question ‘’Does the brain need oxygen?’’ We will review the role of oxygen in the functioning of the brain and the consequences of the lack of this element in the body.

Does the brain need oxygen?

 Yes, the brain needs a constant supply of oxygen and nutrients to function, since brain energy is generated by metabolism that requires oxygen.

Although it represents 2% of our body weight, the brain consumes approximately 20% of the oxygen that we take in, varying the percentages according to the brain area. For example, sensory and motor areas spend more.

This consumption is continuous, since it has very little capacity to store nutrients. Therefore, the lack of oxygen in the brain can have serious consequences.

For the first time, neurobiologists from the Ludwig-Maximilians-Universität (LMU) in Munich (Germany) have managed to relate the level of oxygen directly to the function of certain nerve cells.

Compared to its body mass, the brain consumes a vast amount of energy. This energy is mainly produced by aerobic metabolic processes that use significant quantities of oxygen.

Oxygen levels in the brain are therefore a critical aspect affecting the role of nerve cells and glial cells, the main purpose of which is to assist neurons and which are actively involved in the processing of information in the brain within the body.

To date, however, the amount of oxygen consumed in the brain and how this relates to neuronal activity has been unknown. Given this, the neurobiologists Hans Straka, Suzan Özugur and Lars Kunz, from the German university, have managed for the first time to measure that amount of oxygen in an intact brain and correlate it with the activity of nerve cells.


In their study, published in the scientific journal ‘BMC Biology‘, the researchers took an animal model, tadpoles of the clawed frog ‘Xenopus laevis’, and determined, with the help of electrochemical sensors, the concentration of oxygen in the brain and in one of the cerebral ventricles.

“We were able to show that only about 50 percent of oxygen is used for nerve cell activity during normal function.”

The researchers recorded the relationship between oxygen consumption and nerve cell activity. How did they do it? Using the model of neurons that control eye movements, they controlled the amount of oxygen in the brain and inhibited the activity of neurons with the application of drugs.

“We have discovered that the brain is anoxic (lacks oxygen) in a normal environment saturated with air, which means that oxygen cannot be measured,” explains Straka in statements collected by Neuroscience News. “Therefore, the cells immediately used the full oxygen to synthesize energy-rich substances.”

Better understand the consequences of oxygen deprivation

“We were also able to show that only about 50 percent of oxygen is used for nerve cell activity during normal operation,” Straka adds. “So the other 50 percent is needed for glial cells and to maintain the basic metabolic rate of nerve cells. However, more active nerve cells consume more oxygen.”

Understanding the relationship between the amount of oxygen and brain activity is of the utmost importance. The results of this study have shed little light on better understanding how information is processed in the brain and have created a basis for future research.

Even the contributions of this type of research are incredibly important for medicine, understanding this relationship will allow us to better understand the consequences of a lack of oxygen in the brain.

What happens to the brain if it does not have oxygen?

The brain can last 4-5 minutes without oxygen. Now, once that time has passed, cellular damage begins to occur, which will be greater the longer it passes. In fact, if the lack of oxygen is maintained for more than 15 minutes, at least 95% of the brain tissue will be damaged.

The lack of oxygen in the brain constitutes an encephalopathy called anoxia, if the deprivation is total, or hypoxia, if it is partial.

The lack of oxygen in the brain can be due to several reasons. Generally, it is caused by cardiocirculatory or respiratory failure. However, there are other reasons that can cause this injury and that constitute the classification of anoxia:

Anoxic anoxia

This anoxia is caused by breathing insufficient oxygen. For example, when you go to places of very high altitude and the oxygen concentration is lower. Or from drowning, severe asthma, choking, etc.

Anemic anoxia

It occurs due to a decrease or alteration in the ability of hemoglobin to oxygenate the blood.

Ischemic anoxia or hypoxia

In this case, the reduction in cerebral flow or blood pressure causes an inadequate supply of oxygen. This occurs for example in a stroke, cerebral hemorrhage or cardiac arrest. The latter are the most common cause of brain damage due to lack of oxygen.

  • Lack of oxygen in neonates

It is well known that perinatal hypoxia can have mild to severe consequences, being the main cause of brain damage and neurological sequelae in children.

Approximately 5% occur in the time before delivery, 85% during delivery, and 10% in the neonatal period. The causes of damage are usually due to compressions to the umbilical cord, placental abruption or poor conduction of blood from the mother to the fetus, among others.

Toxic anoxia

The lack of oxygen in the brain can also occur due to the consumption of substances that interfere with the use of oxygen. For example, due to poisoning by carbon monoxide, alcohol, acetone and even by some anesthetics.


Ultimately, the consequence of oxygen deprivation is brain damage and even death. More specifically, the lack of oxygen first produces a loss of consciousness or coma. After this period it could fall into a vegetative state.

If the person regains consciousness, then symptoms similar to those of a head injury occur. Thus, the severity of the damage and the symptoms will depend on the characteristics of the anoxia and personal: duration, age of the person, if another associated disease is suffered, the duration of the coma and the extent, location and spread of the lesion.

Cognitive diseases

In relation to cognitive functions, the main symptom is loss of short-term memory or learning ability. This appears to be due to the fact that the hippocampus, an area highly involved in learning new information, is highly sensitive to oxygen deprivation.

On the other hand, anoxia can affect executive functions, causing the person to be more impulsive, indecisive and have difficulties reasoning and processing information.

Visual disturbances can also occur, even cortical blindness can occur. That is, the image is received but it cannot be processed on a conscious level, therefore the person cannot see. However, those who suffer from it, act as if they saw, but being unable to identify colors, shapes or objects.

Physical alterations

In addition, the lack of oxygen can cause physical disorders, such as lack of coordination (ataxia), which is an obstacle to walking correctly.

Or apraxia, which is the inability to properly perform the sequence of everyday tasks, such as brushing your teeth. Body stiffness, jerking or involuntary movements, as well as limb weakness can also occur.



After an episode of anoxia or hypoxia, epilepsy or a similar picture consisting of seizures or muscle jerks may also develop.

Also, especially if the anoxia is in a neonate, cerebral palsy can occur. On the other hand, it is common to find disorders in the level of consciousness, where prolonged states of low response to the environment occur.

Can it be prevented?

Although there is a margin where people cannot control an accident happening to us, certain measures can be taken that can help us prevent anoxia or hypoxia, both for ourselves and for people around us.

In the case of children, it is important to ensure that they are not exposed to risks of suffocation, such as chewing food carefully or using small parts games. It is also important to learn to swim and not leave children alone in pools, bathtubs or the sea.

In relation to the above, cardiopulmonary resuscitation techniques can be learned, as well as the Heimlich maneuver to avoid choking. You can also control your carbon monoxide levels at home and avoid taking drugs or non-prescription medications.

How can I oxygenate my brain?

Oxygenating your brain is not just about physical health. It helps you make faster, more congruent and in short, wiser decisions. And is that the brain is itself, the engine of our body without which nothing would make sense.

These are some examples that will tell you how to productively oxygenate your brain. If you put them into practice, you will become more assertive, you will think better about your strategies and you will make decisions faster.


With yoga breathing you re-educate your body to use and improve lung capacity for its own benefit. Tissue oxygenation is improved, blood flow is accelerated, and unwanted emotional response patterns are controlled because attention and concentration are improved.


Walking works for seniors, and if you’re out of shape, jogging works too. However, running makes your brain need more oxygen and your body forces itself to do the job.

At first it can be exhausting and tedious, but if you watch your breath and do it constantly, you will soon realize that you can even enter a state of relaxation in which your body and mind are more connected than ever.


Meditation is more difficult than it sounds. Just as we were talking about how when running you can enter a trance, meditating seeks to free the brain and make you stop thinking, keep your mind blank, again, it is a trance. Here you can see how to start meditating and rest assured that soon the results will be visible.

They say that by getting up and breathing or by staying balanced with just one foot on the floor you can oxygenate your brain, but the three aforementioned methods are much more reliable. Remember that food is always the basis of all physical well-being, so you should not stop eating in the best possible way

FAQS: Does the brain need oxygen?

What are the symptoms of lack of oxygen to the brain?

Symptoms of hypoxia

  • Headaches.
  • Fatigue or tiredness
  • Dyspnea or shortness of breath
  • Palpitations can be seen in the initial phases of hypoxia. …
  • Increased blood pressure in the initial phases of hypoxia is followed by lowered blood pressure as the condition progresses.
  • Nausea and vomiting.

How does the brain get oxygen?

Its nutrients (oxygen and glucose) are obtained from the blood that it receives thanks to a huge network of blood vessels that reaches almost 650 kilometers in length.

How important is oxygen to the brain How long can the brain survive without oxygen?

A healthy brain cell, a neuron, can go five to 10 minutes without receiving oxygen. After that time, he begins to suffer injuries that will be irreversible.

What percentage of oxygen does the brain use?

The brain uses 20% of the oxygen and blood in your body

Can the brain heal after lack of oxygen?

Complete recovery from serious anoxic or hypoxic brain injury is rare, but full or partial recovery is likely in many patients with moderate anoxic or hypoxic brain injury.

In this post we are going to answer the question ‘’Does the brain need oxygen?’’ We reviewed the role of oxygen in the functioning of the brain and the consequences of the lack of this element in the body.


How Much Oxygen Does the Brain Need? – Neuroscience News. Retrieved November 20, 2020, from Neuroscience News website

‌Study Reveals Brain’s Finely Tuned System of Energy Supply. (2016, August 8). Retrieved November 20, 2020, from URMC Newsroom website

Neurobiology: How much oxygen does the brain need? (2020). Retrieved November 20, 2020, from ScienceDaily website