What is Hypoxia: Types, Causes, Symptoms, Complications, Diagnosis, Prognosis, Treatment and Prevention


Hypoxia literally means “low oxygen level,” but it is defined as a deficiency in the amount of oxygen that reaches the tissues of the body.

Unlike hypoxemia , which means an inadequate amount of oxygen traveling in the blood.

Hypoxia can be due to hypoxemia, for example, if an inadequate amount of oxygen reaches the tissues because there is an inadequate amount of oxygen in the blood, or it can also be due to other causes.

The lack of oxygen in tissues is also known simply as “lack of oxygen”. If the lack of oxygen occurs in the tissues, it is called anoxia.

Hypoxia can affect the entire body (generalized hypoxia), or a specific organ or area of ​​the body (tissue hypoxia) .

It can also be classified as acute or chronic, acute when it has a rapid onset, and chronic when hypoxia has been ongoing for some time.


As noted earlier, there are different types of hypoxia, or reasons why there is not enough oxygen in the tissues of the body. These include:

Hypoxic hypoxia or hypoxemic hypoxia:

In this type of hypoxia, the tissues do not have enough oxygen because there is a lack of oxygen in the blood that flows to the tissues.

Hypoxic hypoxia can be caused by inadequate breathing, as well as other causes.

Anemic hypoxia:

In the context of anemia, low levels of hemoglobin results in a decrease in the ability of blood to transport oxygen that is breathed, and therefore, a decrease in the supply of oxygen available to tissues.

Anemia can be caused by many conditions.

Stagnant hypoxia or circulatory hypoxia:

This form of hypoxia is caused by inadequate blood flow, which results in less oxygen availability in the tissues.

Histotoxic Hypoxia:

An adequate amount of oxygen is inhaled through the lungs and carried to the tissues, but the tissues can not use the oxygen that is present.

Metabolic hypoxia:

It occurs when there is more oxygen demand in the tissues than usual. Oxygen can be absorbed, transported and used correctly by tissues, but due to a condition that increases metabolism, oxygen is not enough.

An example of this is sepsis (a severe and overwhelming infection.)

The symptoms

Cognitive symptoms:

• Loss of short-term memory. This is the most common, almost universal symptom of hypoxia. This refers to the storage and sensitivity / recognition of the information that has just been presented.

The most significant impact of short-term memory loss for a person with hypoxia is that the ability to retain and recall new or unknown information is impaired.

• Behavioral changes. The person can become more verbally and physically aggressive. They may also have problems with disinhibition (ie, “socially unacceptable behaviors”).

Motivation can also be a problem, the person is unable to carry out a simple activity

• Difficulties with executive functioning, such as reasoning, judgment, initiation and impulsivity.

• Visual disturbances – some people with hypoxia may have difficulty processing visual information. They may have double vision or “islands” of vision (like partial vision).

Physical effects may include:

• Movement – “Ataxia” – difficulties with body / motor coordination. These symptoms are often confused with individuals intoxicated with alcohol.

• Spasticity, movements of rigidity, oppression of body movements.

• Partial or total paralysis, however with time some movement can recover.


A person with a hypoxic injury can have difficulties in communication, in the search for words or make sentences.

Two common forms of communication difficulties are:

• “Dysphasia” / “Aphasia” – anomaly in the use of language or word coordination.
• “Dyspraxia” – lack of coordination of speech muscles (not associated with muscle weakness)

The most common causes

  • Cardiac arrest (myocardial infarction).
  • Severe asthma attack.
  • Drug overdose or poisoning.
  • Seizures, such as epilepsy.
  • Attempt suicide (hanging) or near drowning.
  • Severe blood loss
  • Anesthesia accidents.
  • Electrocution.

What are the complications of hypoxia?

Hypoxia is a serious problem that, if not addressed immediately, can cause serious and permanent damage or even death.

Brain damage and paralysis due to hypoxia: the main complication of hypoxia is permanent brain damage and paralysis. This is very prominent in postnatal cases in which, within 48 hours after birth, the baby experiences permanent brain damage and paralysis in the face of complete hypoxia.

Approximately 1/3 of all neonatal deaths are attributed to hypoxia, according to reports from the US National Institute of Health. UU

Brain death and vegetative state: this means that there will be breathing, opening of the eyes, blood pressure, etc. (basic functions of life), but the person will not respond to the surroundings or will not be alert. Within a year or so, the person will die.

During this period, malnutrition and bed rest will be common and obvious consequences.

Hypoxia that leads to cerebral palsy: when the brain does not receive enough oxygen, complications such as damage to the brain tissue that results in cerebral palsy occur.

Five minutes after the oxygen supply to the brain is cut off, brain cells begin to die rapidly, leading to cerebral palsy.

Necrosis or tissue death as a complication of hypoxia: hypoxia can cause the death of body tissue or necrosis.


Symptoms help the doctor diagnose the condition and identify the cause of the hypoxia. In case a person, especially a child is in a state of hypoxia for more than 5 minutes, the doctor will take the necessary measures to prevent the condition from getting worse.

This can be done without being admitted to the hospital or medical care, in case it is a less serious problem, such as caused by environmental conditions. Otherwise, for serious complications, admission to the hospital is essential.


The acute treatment of hypoxia is to establish an adequate airway as soon as possible, with enough oxygen to saturate the blood, support the cardiovascular system, as necessary.

Treatment of the cause of decreased oxygen supply to the brain may include surgical intervention.

Once the person’s respiratory and cardiovascular system is adequately reestablished, the person will move on to the initial phase of recovery.

As recovery progresses, a variety of psychological and neurological symptoms may appear, and some individuals may need support in an isolated and safe environment, when confusion and turmoil are very evident, in order to prevent them from causing harm to themselves. themselves or others.

Oxygen therapy for hypoxia: the supply of oxygen to the lungs is the method of immediate treatment that should be followed in case of hypoxia. For that, a mechanical device is used to supply prescribed oxygen.

This immediately increases the oxygen in the blood, relieves the patient from shortness of breath and helps the functionality of the lungs and other organs of the body.

Oxygen tanks are used for the supply of oxygen through masks or nasal or oral tubes that are inserted directly into the trachea.

Sometimes, liquid oxygen is used because it requires less space for storage. However, the main problem with liquid oxygen is as soon as liquid oxygen leaves the vessel, it evaporates.

Medications to treat hypoxia: medications play such an important role in the treatment of hypoxia as oxygen therapy.

If the cause of the hypoxia is asthma or other health problems, they should be taken care of immediately. In addition to treating the causative factors with medications, it is equally important that you treat the symptoms.

  • Medications should be taken to treat blood pressure.
  • Cardiac medications should be taken to control chest pain and heart failure.
  • Medications for allergy.
  • Medications to control GERD or  acid reflux .


Recovery depends on the severity of the injury. The direct treatment is limited and, therefore, the focus is on the stabilization of the person and participation in rehabilitation services.

Rehabilitation and recovery can take years. A good working relationship with rehabilitation specialists is very important.

Expectations may not correspond to the current levels of the person in progress, and the potential for disappointment and / or conflict may be high.

Working together is a way to help maximize the person’s potential and ensure that the person can continue to live in a less restrictive environment.

It is important to understand that each person’s recovery is unique and different results are produced for each patient.

Prevention of Hypoxia

  1. Early recognition of symptoms
  2. The proper use of oxygen equipment.
  3. Good maintenance of the oxygen equipment.
  4. Preliminary check all oxygen equipment.
  5. Strict adherence to oxygen needs (required above 12,500 feet).