Cerebral Hypoxia

Cerebral hypoxia happens when your brain doesn’t get enough oxygen. Symptoms include confusion, difficulty speaking and seizures. It’s a medical emergency that can be fatal and can cause lifelong brain damage. Healthcare providers can treat some of the issues that cerebral hypoxia causes but they can’t reverse the brain damage that it can cause.


What is cerebral hypoxia?

In cerebral hypoxia, your brain doesn’t get enough oxygen. That can happen if you can’t breathe or if something prevents blood, which carries oxygen, from getting to your brain. Without oxygen, your nervous system can’t send nerve signals and messages throughout your body so you breathe, move, speak and see.

Many things can cause cerebral hypoxia, from cardiac arrest to head injuries to inhaling smoke. No matter how it happens, cerebral hypoxia is a medical emergency that requires immediate medical care to restore oxygen flow to your brain. It can be life-threatening or cause significant lifelong health issues.

Healthcare providers may use the term hypoxia-anoxia injury to describe cerebral hypoxia. In anoxia, you aren’t getting any oxygen at all, while cerebral hypoxia means you’re getting some oxygen, but not enough to meet your brain’s needs.


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Symptoms and Causes

What are cerebral hypoxia symptoms?

Symptoms vary depending on how long your brain goes without getting enough oxygen. Your brain cells start dying within minutes of low oxygen. At first, symptoms may include:

Later, symptoms become more obvious and may include:

The more severe symptoms include loss of consciousness and coma.

What causes cerebral hypoxia?

Cardiac arrest is the most common cause in the U.S. But you can develop cerebral hypoxia any time something interrupts the flow of oxygen to your brain. For example, certain systemic illnesses may cause it, like severe anemia, systemic hypotension (low blood pressure) or systemic hypoxia (low oxygen levels in your body tissues). Other causes include:


What are the complications of cerebral hypoxia?

The most significant and severe complications include:

Diagnosis and Tests

How is cerebral hypoxia diagnosed?

A healthcare provider may order tests to find out how lack of blood flow affects your brain. Tests may include:


Management and Treatment

What are the treatments for cerebral hypoxia?

Healthcare providers start treatment by identifying the underlying cause and restoring the flow of oxygen to your brain, like using mechanical ventilation to help you breathe or treatments to help oxygen-rich blood flow to your brain.


Can cerebral hypoxia be prevented?

Unfortunately, you may not be able to prevent all issues that can cause cerebral hypoxia, like accidental near-drowning or choking. But you can take steps to lower your risk of accidents that cause cerebral hypoxia. For example, you can:

  • Install smoke detectors and carbon monoxide detectors in your home. Be sure to do regular checks to make sure they’re working.
  • Make sure everyone buckles their seatbelts anytime they’re in a motor vehicle.
  • Use life vests, swim at places that have lifeguards and supervise children around water, including bathtubs.
  • Wear helmets during high-impact physical activities or while biking, skating or skiing.

Medical issues like cardiac arrest, heart attack and stroke increase your risk of cerebral hypoxia. While you may not be able to prevent them from happening, you can reduce your risk by:

  • Improving your lifestyle. Adding regular exercise to your daily routine and eating well with food choices based on plans like the Mediterranean diet or DASH may reduce your risk of heart attack and stroke.
  • Know your cardiac arrest risk. Talk to a healthcare provider about your concerns and your medical history. They may order tests that evaluate your risk of cardiac arrest, like an electrocardiogram (EKG) or electrophysiology (EP) study.
  • Avoid risky lifestyle choices. Smoking and tobacco use, recreational or prescription drug misuse, or drinking excessive amounts of alcohol increase your risk of heart attack and stroke.
  • Manage underlying conditions. Conditions like diabetes, high blood pressure, high cholesterol levels (hyperlipidemia) and having obesity increase your risk of heart attack and stroke.
  • Get regular medical checkups. Visit your primary care provider for an annual wellness check so they can look for signs of issues that increase your risk of cerebral hypoxia.

Outlook / Prognosis

What is the outlook for cerebral hypoxia?

The outlook varies depending on your situation. In general, the outcome depends on factors like:

  • How long you had low oxygen levels. Brain damage begins within four minutes of not having enough oxygen. The longer your brain lacks oxygen, the more likely you’ll have brain damage.
  • The underlying cause. For example, one study shows most people who had cerebral hypoxia after a heart attack have significant issues with cognition (how they process thought).
  • If the condition caused a coma, how long the coma lasts. For example, studies suggest a person who comes out of a coma in fewer than four weeks has fewer long-term complications than someone who remains in a coma for longer periods.

Living With

How do I take care of myself?

Cerebral hypoxia can affect your ability to speak, walk or control your movements. If that’s your situation, you’ll need medical support like physical therapy or speech therapy. And it may take months before you’re fully recovered, so try to be patient as you work to get well.

My family member has severe cerebral hypoxia. How do I take care of them?

Severe cerebral hypoxia is a serious medical condition that can be life-threatening. In some cases, it causes coma, which may last for a few weeks or shift to being in a vegetative state. Either way, your family member will be unconscious and will need ongoing care in a hospital setting or a rehabilitation center.

When should I seek care?

Cerebral hypoxia is a medical emergency. If you have symptoms — even seemingly harmless ones like dizziness or confusion — call 911 or ask someone to take you to the emergency room. Call 911 if you’re with someone who’s having symptoms, including:

  • Loss of consciousness.
  • Seizures.
  • Shallow breathing.
  • Signs of cardiac arrest, heart attack or stroke.

What questions should I ask my doctor?

If you’re recovering from mild cerebral hypoxia, you may want to ask the following questions:

  • Do you know why this happened?
  • Could it happen again?
  • What are potential complications?

If a family member or loved one has cerebral hypoxia and can’t speak for themselves, you may want to ask the following:

  • How severe is the brain injury?
  • What are the potential complications?
  • Can any medications help improve my family member’s symptoms?
  • What’s the long-term prognosis?

A note from Cleveland Clinic

Cerebral hypoxia can happen to anyone and cause life-changing or life-threatening medical issues. There’s no way to prevent the condition. But there are ways to reduce your risk, starting with taking care of your overall health. For example, receiving treatment for high blood pressure that may cause heart attack or stroke can reduce your risk. Talk to a healthcare provider about protecting your overall health. Those conversations may help you avoid cerebral hypoxia and other serious medical issues.

Medically Reviewed

Last reviewed on 03/08/2024.

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