Lazarus Effect / Phenomenon

The Lazarus effect (autoresuscitation) is when someone declared dead from cardiac arrest suddenly shows signs of life, usually within 10 minutes of CPR ending. This makes it seem like they’ve come back to life, but in fact they hadn’t died. This is a rare phenomenon, and healthcare providers don’t know the exact cause.

What is the Lazarus effect?

The Lazarus effect is when someone a healthcare provider has declared dead suddenly regains blood flow and appears to come back to life. The medical term for this phenomenon is “autoresuscitation,” which refers to the return of spontaneous circulation after cardiopulmonary resuscitation (CPR) has ended. Most people don’t survive for long after the brief return of blood flow.


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The Lazarus effect is rare in medical literature. However, the possibility of the dead coming back to life holds a much larger place in popular culture. The name “Lazarus” refers to the Biblical story of Jesus bringing a man back from the dead.

But this term is a bit misleading in the context of medical autoresuscitation. That’s because people who experience the Lazarus effect don’t actually die and resurrect. Instead, their vital signs indicate their organs have stopped functioning when in fact there’s just a delay in the return of blood flow after CPR. This delay makes it look like a person has died and then come back to life.

Other names for the Lazarus effect include:

  • Lazarus phenomenon.
  • Lazarus syndrome.
  • Autoresuscitation after failed cardiopulmonary resuscitation.

What is the definition of the Lazarus effect?

Healthcare providers define autoresuscitation as the return of spontaneous circulation after CPR has ended. This means your heart begins beating again without help and can send blood to your organs and tissues. Here’s the basic order of events that qualify a specific case as autoresuscitation:

  1. A person has cardiac arrest.
  2. A healthcare provider or someone else begins performing CPR.
  3. The individual giving CPR determines it’s not helping and concludes the person has died.
  4. A medical professional authorized to make the call declares the person clinically dead. No one performs any further medical interventions.
  5. Minutes or even hours later, someone notices signs of life. These could be movements or indications of breathing. The signs must last for more than a few seconds.
  6. A healthcare provider determines the person’s circulation has returned, and active medical care resumes.

It’s not always clear how much time has passed between the declaration of death and the spontaneous return of blood flow. Based on reported cases, someone usually notices signs of life within 10 minutes of CPR ending. But it’s sometimes longer. In some cases, there may be a gap between the return of a person’s blood flow and the point when others notice.

How common is the Lazarus effect?

There are 65 documented cases in medical literature from 1982 to 2018. Of those, 18 people made a complete recovery.

Researchers believe this phenomenon is more common than the documented numbers reveal. But they don’t know exactly how common it is or who’s more likely to experience it. Of the known cases, most people (68%) were over age 60.

Where can this happen?

Autoresuscitation has occurred both in and out of hospitals. It’s always after someone has received CPR.

What causes the Lazarus phenomenon?

Healthcare providers don’t know exactly why this happens. One theory suggests CPR quickly pushes lots of air into your lungs, leading to hyperinflation. In other words, there’s too much air in your lungs and not enough time for you to breathe it out. As a result, the pressure in your chest increases.

This raised pressure limits how much blood can flow into and out of your heart. When CPR stops, the pressure drops, and blood can again flow to your heart. This may cause circulation to resume, but often only briefly.

Most people don’t survive for long after the brief return of blood flow. Therefore, healthcare providers try to lower the chances of a delayed return of circulation and/or a premature declaration of death. Preventing the Lazarus effect can help caregivers and family members avoid the upset of having a brief spark of hope that’s soon extinguished.

How can you prevent the Lazarus phenomenon?

Regardless of the underlying cause, the Lazarus effect can only occur after a healthcare provider declares someone clinically dead. Because of this, researchers have offered guidelines for providers to lower the odds of a premature declaration of death. These include:

  • Performing CPR for at least 20 minutes.
  • Taking steps to avoid hyperinflation during CPR. For example, some CPR guidelines suggest giving a maximum of 12 breaths per minute.
  • Not stopping CPR immediately after defibrillation (which can temporarily cause asystole, or “flat-lining”).
  • Monitoring a person nonstop for 10 minutes after CPR has ended before declaring death.

Thinking about situations where you’d need CPR may make you feel helpless. But you can take an active — and proactive — role in your care by making early decisions about end-of-life measures.

For example, decide if you want CPR or other forms of life support. Share these wishes with your healthcare provider and your loved ones. You may also choose to designate a healthcare power of attorney. That’s someone who can make medical decisions on your behalf. These are never easy decisions, but planning ahead as much as possible can give you and your loved ones peace of mind.

A note from Cleveland Clinic

While the Lazarus effect is rare, CPR and attempts to save someone’s life happen in the medical world every day. So, reading about this phenomenon can be a good reminder to learn more about life support and end-of-life care. Talk to your provider about your options and how to put your preferences into writing.

Medically Reviewed

Last reviewed by a Cleveland Clinic medical professional on 04/04/2023.

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