Dr. Ngo measuring a patient's heart rate

How long can the brain go without oxygen?

A brain injury is a debilitating and frightening experience for victims and anyone who witnesses the confusion and desperation victims go through. While many brain injuries result from physical trauma, an equally significant number are caused by oxygen deprivation, which can result from a variety of factors.

According to the National Institutes of Health, the human brain can survive without oxygen for up to four or five minutes. During this time, the brain is not capable of functioning at anything near its normal capacity. Extensive and irreversible brain damage may occur through cell death if oxygen levels are not restored quickly enough after this period.

How Lack of Oxygen Affects the Brain

As one of the most complex organs in the body, the brain relies on a steady supply of oxygen to function properly. If a person isn’t cycling enough oxygen regularly through their respiratory system, their brain can start to malfunction, possibly leading to damage, disability and even death.

The effects of oxygen deprivation on the brain depend on the degree of deprivation and how long it lasts. In general, however, the longer the deprivation lasts, the more severe the effects will be.

Signs and symptoms include:

  • Confusion and difficulty thinking clearly
  • Difficulty concentrating
  • Extreme changes in mood
  • Seizures
  • Slurred or slowed speech
  • Poor balance
  • Unresponsiveness

If the person suffering from lack of oxygen to the brain doesn’t receive medical intervention quickly enough, they may suffer extensive or irreversible brain damage, fall into a coma, or die.

Types of Brain Injury from Oxygen Deprivation

Hypoxic and anoxic brain injury are the two main types of brain injury resulting from oxygen deprivation.

Hypoxic Brain Injury

Hypoxic brain injuries (HBI) are caused by the gradual restriction of oxygen flow to the brain. In most cases, the injury is caused by a medical incident or emergency, such as a heart attack or stroke. If an individual does not receive immediate medical attention or help to restore oxygen flow, the brain suffers irreversible damage, possibly leading to death.

The severity of an HBI depends on several factors, including how suddenly the oxygen was lost, how soon the victim received medical help, and how well the victim responded to the treatment that was applied.

However, regardless of its severity, HBI is always a serious injury that requires prompt diagnosis and treatment.

Anoxic Brain Injury

Anoxic brain injury (ABI) is a serious and potentially life-threatening complication following an episode of hypoxia or complete deprivation of oxygen.

Hypoxia can occur due to several factors, including congenital heart disease, respiratory failure, and severe burns. In some cases, it can be caused by prolonged exposure to low levels of oxygen in air or water.

ABI is classified based on the level of oxygen deprivation experienced by the victim. In the most severe cases, victims experience complete anoxia (zero oxygen in the blood), leading to cell death and tissue damage.

Victims with lesser levels of oxygen deprivation experience various degrees of anoxic brain injury, affecting their ability to think clearly, remember events, and respond physically.

Read about Glen Allen’s recovery journey

ABI can be life-threatening in many ways. The most common complication is brain damage, which can result in memory loss, impaired thinking skills, and even death. Other potential complications include seizures, coma, and paralysis.

Most victims of ABI recover fully with appropriate treatment. However, without prompt and comprehensive medical treatment, the long-term outlook is usually grim, with significant cognitive impairment and a high risk of developing other chronic disabilities.

If not properly addressed, ABI may cause permanent neurological damage.

Hypoxic and Anoxic Brain Injury Treatment Options

As with many types of brain injury, there is no one-size-fits-all approach to treating either hypoxic or anoxic brain injury. The best treatment plan will vary depending on the severity of the injury, and the individual’s health and medical history.

That said, there are several treatment options available that can help restore function and improve outcomes for patients


Rehabilitation therapies can help restore function and improve motor skills, cognitive function, and emotional stability after suffering a hypoxic or anoxic brain injury. Rehabilitation may be undertaken on an inpatient or outpatient basis, depending on the individual’s particular status and needs.

Inpatient rehabilitation may include physical therapy, occupational therapy, speech therapy, and psychological counseling.

Outpatient rehabilitation may include shorter but more frequent sessions, such as home exercises, visits to a therapist, or other combination of treatments as needed, as is the case with our Brain Injury Day Treatment and Brain Injury Clubhouse programs.

Neuroprotective Measures

Neuroprotective measures may help reduce the damage caused by HBI and promote recovery. These measures can include promoting blood flow to the brain, protecting neurons from damage, and reducing inflammation in the brain.

Some neuroprotective measures, such as medication or surgery, require prior approval from a doctor. Others involve physical activity like participation in adaptive sports and recreation or meditation

Rehabilitation Programs for Children and Adults with HBI

There is a growing trend of rehabilitation programs specifically designed for adults and children with HBI.

These programs include various forms of physical therapy, psychotherapy, cognitive rehabilitation, occupational therapy, speech therapy, and psychological counseling.

Patients may require breathing assistance through a tube in their throat or a mechanical ventilator, depending on the severity of the anoxic brain injury.

They may also require intensive rehabilitation to help them relearn basic daily tasks, such as swallowing and speaking. In some cases, intensive medical care may be required for years.

If you or a loved one is a brain injury victim, it is important to provide support and assistance during recovery. You can seek help from a healthcare professional or support group to help you understand the victim’s condition and how best to help them.

Learn More About Hypoxic and Anoxic Brain Injury Treatment at Brooks Rehabilitation

Whatever the cause or type of brain injury, victims and their loved ones experience incalculable depths of trauma, stress and loss.

At Brooks Rehabilitation, we understand your pain, frustration and confusion when it comes to seeking the right treatment for your particular circumstances. We strive to provide the most comprehensive, compassionate care to ensure the best outcomes possible for everyone touched by the tragedy of a brain injury.

With our fully equipped facilities and loving community of qualified and experienced staff, you can be certain that you or your loved one will receive the best care and treatment.

Make an appointment today with our representatives, and start the journey to reclaim your lives.

Translate »