What Physically Happens When You Die?

It is natural to wonder what happens when you die. From a physical standpoint, death occurs when the body's vital functions stop entirely, including respiration (breathing), heart function, and, finally, brain function. The actual moment of death is part of the process of dying in which these functions shut down, sometimes gradually and, in others cases, abruptly.

After death, the body undergoes changes in a consistent pattern as the body temperature drops, skin color and texture change, and muscles relax, stiffen, and then relax again.

Here is a timeline of the changes the body undergoes during the process of dying and death. This article walks you through the processes from the moment a person dies right through the various post-mortem (post-death) stages.

What Happens at the Moment of Death?

The moment of death is not necessarily painful. While people with certain medical conditions may feel pain at the end of life, others die painlessly. Often, people with terminal conditions like cancer receive pain medication so they are comfortable at the moment of death.

We often think of the moment of death as that time at which the heartbeat and breathing stop. We are learning, however, that death isn't instantaneous. Our brains are now thought to continue to "work" for 10 minutes or so after we die, meaning that our brains may, in some way, be aware of our death.

In the hospital setting, there are a few criteria doctors use to declare death. These include the absence of a pulse, the absence of breathing, the absence of reflexes, and the absence of pupil contraction to bright light.

In an emergency setting, paramedics look for the five signs of irreversible death to determine when resuscitation, or revival, is not possible.

By definition, death is either when circulatory and respiratory functions stop irreversibly, or brain death, when the entire brain, including the brainstem, stop functioning. The determination must be made according to accepted medical standards.

What Happens One Hour After Death?

At the moment of death, all of the muscles in the body relax, a state called primary flaccidity. Eyelids lose their tension, the pupils dilate, the jaw might fall open, and the body's joints and limbs are flexible.

With the loss of tension in the muscles, the skin will sag, which can cause prominent joints and bones in the body, such as the jaw or hips, to become pronounced. As muscles relax, sphincters release and allow urine and feces to pass.

Within minutes of the heart stopping, a process called pallor mortis causes the body to grow pale as the blood drains from the smaller veins in the skin. This process may be more visible in those with light skin rather than darker skin.

The human heart beats more than 2.5 billion times during the average human lifespan, circulating about 5.6 liters (6 quarts) of blood through the circulatory system.

At the same time, the body begins to cool from its normal temperature of 98.6 F (37 C) until reaching the air temperature around it. Known as algor mortis or the "death chill," body temperature falls at a somewhat steady rate of 1.5 degrees F per hour.

The expected decrease in body temperature during algor mortis can help forensic scientists approximate the time of death, assuming the body hasn't completely cooled or been exposed to extreme environmental temperatures.

What Happens 2 to 6 Hours After Death?

Because the heart no longer pumps blood, gravity begins to pull it to the areas of the body closest to the ground (pooling), a process called livor mortis.

If the body remains undisturbed for several hours, the parts of the body nearest the ground can develop a reddish-purple discoloration resembling a bruise caused by the accumulation of blood. Embalmers sometimes refer to this as the "postmortem stain."

Beginning anywhere from 2 to 6 hours after death, chemical changes within the body's cells cause all of the muscles to begin stiffening, known as rigor mortis. With rigor mortis, the first muscles affected will be the eyelids, jaw, and neck.

Over the next several hours, rigor mortis will spread into the face and down through the chest, abdomen, arms, and legs until it finally reaches the fingers and toes.

Interestingly, the old custom of placing coins on the eyelids of the deceased might have originated from the desire to keep the eyes shut since rigor mortis affects them soonest. Also, it is not unusual for infants and young children who die to not display rigor mortis, possibly due to their smaller muscle mass.

What Happens 7 to 12 Hours After Death?

Maximum muscle stiffness throughout the body occurs after roughly 12 hours due to rigor mortis, although this will be affected by the person's age, physical condition, gender, the air temperature, and other factors.

At this point, the limbs of the deceased are difficult to move or manipulate. The knees and elbows will be slightly flexed, and fingers or toes can appear unusually crooked.

What Happens 12 Hours After Death?

After reaching a state of maximum rigor mortis, the muscles will begin to loosen due to continued chemical changes within the cells and internal tissue decay. The process, known as secondary flaccidity, occurs over a period of one to three days and is affected by external conditions such as temperature. Cold slows down the process.

During secondary flaccidity, the skin will begin to shrink, creating the illusion that hair and nails are growing. Rigor mortis will then dissipate in the opposite direction—from the fingers and toes to the face—over a period of up to 48 hours.

Once secondary flaccidity is complete, all of the muscles of the body will again be relaxed.

Summary

Death is declared when there is either brain death or all efforts to resuscitate a person have failed. From the moment of death, physical changes will start to take place:

• Within one hour: Primary flaccidity (relaxation of muscles) will occur almost immediately followed by pallor mortis (paling of the skin).
• At two to six hours: Rigor mortis (stiffening of muscles) will begin.
• At seven to 12 hours: Rigor mortis is complete.
• From 12 hours: Secondary flaccidity will start and be completed within one to three days.

A Word From Verywell

Some people do not want to think about the changes in the body after death, whereas others wish to know. Everyone is different, and it is a very personal decision.

For those who wish to know, however, we are learning that the bodily changes leading up to death, and after death, aren't simply random decomposition. Our bodies are actually designed to shut down and die at some time in a programmed manner.