05/11/2026
The Lazarus effect (phenomenon) is when someone a healthcare provider has declared dead suddenly regains blood flow and appears to come back to life. This may show up as a return of pulse, an organized heart rhythm on the monitor or even improved color. Occasionally, there may appear to be limited purposeful movement. Unfortunately, most people don’t survive for long after the brief return of blood flow.
Experts don’t know exactly why autoresuscitation happens. One theory suggests CPR may quickly push lots of air into your lungs, leading to hyperinflation. In other words, there’s so much air in your lungs and not enough time for you to breathe it out. This raises the pressure in your chest.
The raised pressure limits how much blood can flow in and out of your heart. When CPR stops, the pressure drops. Blood can flow into your heart again. This may cause circulation throughout your body to resume, but usually just for a short time.
Another theory involves delayed effects of medications given during CPR. When blood flow is very poor, drugs like epinephrine may take time to reach the heart. Once circulation improves even slightly, these medications can suddenly take effect and help restart the heart.
The Lazarus effect isn’t a reliable sign of survival and usually doesn’t change the outcome. Rather, it may give false hope in situations where death is likely to happen. (For the few who do survive, it’s thanks to CPR and other lifesaving measures.) For these reasons, healthcare providers take measures to keep it from occurring.
