Patient with intermittent hypoxia
Medical Reviewer: Kenneth Ngo, MD
Last Updated: April 9, 2024

Anoxic Brain Injury and Hypoxic Brain Injury

What is an Anoxic Brain Injury vs. Hypoxic Brain Injury

Anoxic brain injuries and hypoxic brain injuries are different types of injuries according to how much oxygen deprivation the brain experienced. Unlike a traumatic brain injury that is caused by blunt force trauma, these types of brain injuries are caused by a lack of oxygen.

An anoxic brain injury occurs when oxygen flow to the brain is completely cut off. When this happens, brain cell death will begin around four minutes from the time of deprivation.

A hypoxic brain injury is when the flow of oxygen to the brain is restricted. When the brain cannot get enough oxygen, brain cells begin to die gradually, ultimately leading to impairment.

Causes of Anoxic and Hypoxic Brain Injuries

Oxygen deprivation is the cause for both types of brain injuries. Lack of oxygen to the brain can happen for a variety of reasons. A stroke is a common cause, however, oxygen deprivation can also occur if the lungs themselves experience trauma and are not able to take in oxygen properly or if oxygen flow within the body is impaired for any reason.

Types of oxygen restrictions that cause brain injury include:

  • Anemic anoxia: occurs when blood cannot carry enough oxygen or there might not be enough blood in the body to support the oxygen needs of the brain.
  • Hypoxic ischemic injury: is when blood that carries oxygen to the brain cannot reach the brain. This can happen after strokes or pulmonary conditions such as a heart attack or cardiac arrhythmia.
  • Toxic anoxia: this occurs when chemicals or poisons hinder the brain from getting oxygen from blood cells.
  • Anoxic anoxia: a lack of oxygen in the air that results in suffocation.

In other words, if you experience a trauma that affects your body’s ability to take in and/or distribute oxygen, it can have profound effects on the brain as well, even if the initial problem did not originate in the brain.

Because each injury is unique, and the inciting incident may not appear to involve the brain at first, it can be helpful to know what the symptoms of these types of injuries can look like.

Symptoms of Anoxic and Hypoxic Brain Injuries

In many cases, people experiencing oxygen deprivation will lose consciousness initially. If they recover consciousness but don’t receive immediate treatment, they may notice both physical and behavioral symptoms:

Physical impairments:

  • Headache
  • Vision issues
  • Changes in sensory perception
  • Changes in sleep patterns
  • Apraxia (motor skill impairment)
  • Aphasia (difficulty speaking and forming words)
  • Seizure
  • Lack of bowel and bladder control
  • Memory problems

Behavioral changes:

  • Personality changes
  • Depression
  • Poor concentration
  • Mood swings
  • Difficulty communicating
  • Limited attention span
  • Disorientation
  • Forgetfulness
  • Inappropriate behavior

Treatment and Recovery

Each brain injury patient’s treatment journey is different and depending on the goals of the patient, an individualized care plan is key for treatment and recovery. However, here’s a few examples of the kinds of standard treatments that a healthcare provider will recommend for your treatment:

Physical Therapy Exercises

Brain injury patients often come to us experiencing a range of motor issues, from reduced mobility and loss of balance to a total inability to walk or move around without assistance. We will work with you to create a personalized physical therapy plan to help you or your loved one regain mobility.

Occupational Therapy Exercises

The trauma that brain injury patients experience can greatly affect how they live their daily lives. Many people initially think about their job when they think of an occupation, but it also includes normal day-to-day activities. Occupational therapy helps patients re-learn what we call “activities of daily living,” which can include anything that occupies your time and is important for your well-being.

Occupational exercises can range from self-care activities like showering and getting dressed to more complex activities such as those required to work at a job. We will work with you to create an occupational therapy treatment plan that helps you or your loved one get back to life prior to injury.

Cognitive Rehabilitation

Cognition is a technical term for the processes involved in thinking. People who experience traumatic brain injury may face difficulties involving memory, attention, social behavior, safety judgment, and planning and carrying out future actions.

Cognitive impairment impacts a person’s ability to care for themselves, keep appointments, complete tasks, or interact with people appropriately. At stake is the person’s ability to succeed at work, school, or home.

Cognitive rehabilitation therapy aims at restoring a more normal life to the patient that better resembles their abilities prior to injury. Sometimes that involves directly strengthening abilities that have been lost or attenuated. Other times it teaches patients new skills to supplement those that are irrecoverable or will take a long time to return. An example of this kind would be developing a plan for supplementing memory loss with calendars, journals, and alarms.

Psychotherapy Treatment

Brain injury takes a toll on every aspect of the body, including and especially emotional well-being. Patients who experience traumatic brain injury can develop depression, anxiety, emotional dysregulation, and a host of other issues either as a direct result of the injury or as a result of the trauma they experienced.

Suffering trauma to the brain is emotionally overwhelming even for people who never struggled with mental health prior to injury. We strongly recommend that if you experience brain trauma, you consider psychological services as part of your treatment regiment. Our psychologists specialize in helping with the kinds of issues that arise as a result of brain trauma.

Anoxic Brain Injury Recovery Stories

Watch the story of Brooks patient Glen Allen and discover how he was able to learn how to walk again after an anoxic brain injury.

Start on the Path to Personalized Treatment at Brooks Today

If you’re ready to get started with an individualized treatment plan, there are a few ways to reach out to us.


Many patients come to us through a referral from their doctor or hospital. If you or a loved one is currently in treatment, you should talk to your healthcare professional about getting more specialized care from Brooks Rehabilitation.

Reach out to us directly

If you are unsure what your needs might be, or want to learn more about our services, you have a few options. You can use our  form to submit an online request for more information.

We’re looking forward to helping you or your loved one through recovery.

Medical Reviewer

Kenneth Ngo, MD

Medical Director of Brooks Rehabilitation Hospital – University Campus, Medical Director of the Brain Injury Program & Brain Injury Day Treatment Program
Dr. Ngo is Board-Certified in Physical Medicine & Rehabilitation, with a subspecialty board certification in Brain Injury Medicine and has been at Brooks Rehabilitation since 2010. Dr. Ngo provides care for patients with complex, catastrophic neurological and other brain injuries, both inpatient and outpatient through the entire continuum of brain injury rehabilitation.
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