ELi5: What Happens When Someone Is Struck By Lightning?


ELi5: What Happens When Someone Is Struck By Lightning?

In: Physics

Lightning is electricity taken to a massive degree.

It’s about 300million volts and something like 200-300thousand amps.

For reference anything over 50 volts can technically shock you and even milliamps is enough to kill you. If it crosses wrong.

But lightning basically overloads every electrical impulse in your body. And if it passes anywhere near your heart it’s probably game over. You could experience delayed effects too if you survive. Memory loss for example. When I was shocked with 277volts I had jitters(like a sudden shiver randomly) and was told to go to the hospital immediately if I had any discolored urine as well. I imagine lightning is worse.

It will also burn at the entrance and exit. I imagine lightning would be much worse than what I had but it likely means you are burning badly in the head or hand and your foot where it would go to ground.

To understand what happens when someone is struck by lightning we have to look at two different phenomena: indirect lightning strikes and direct strikes, as they have different effects.
Indirect strikes: In the case of indirect strikes a bolt of lightning strikes the ground or a conductive structure near the victim, not the victim directly. Electric current created when the lightning strikes the ground, a metal fence, a tree, or some other conductive material, can be carried from the strike point to a person who is nearby. In this case, the person may suffer electrocution. This is also why you should ignore the advice, given by some, to lie down on the ground during a lightning storm. This will not make you any less likely to be directly struck; you are just not tall enough for it to matter to a lightning bolt whether you are upright or lying down. However, it will significantly increase your risk of injury from the electric current generated by a nearby strike.
Direct strikes: Direct strikes have a very different effect on the person or animal struck. In direct strikes, there is no electrocution. This seems strange until one considers that fact that an electric discharge will follow the path of least resistance, and the path of least resistance is over the surface of the skin, not through the core of the body. With this in mind, it is not surprising that approximately 88% of people who experience direct strikes survive. People directly struck also may present with a very unique kind of temporary marking on their skin called Lichtenberg figures or “ferning”.
So, why do 12% of direct lightning strike victims die? We do not know with certainty, but there are two things that may explain direct lightning strike deaths.
First, as lightning flows over the surface of the body it may flow to the brain via the ears, eye sockets, nasal passages, or mouth, catastrophically deranging the function, not only of the brain, but of the entire autonomic nervous system, the system that regulates all all of the organs of the body. This theory is reinforced by the fact that even when people survive direct strikes they usually have neurological symptoms, including impaired memory, confusion, emotional lability, headaches, sensory impairments, and others. These symptoms usually improve over time, but can be permanent.
The second possible mechanism of death may be cardiac arrhyrhmias caused by electric polarization. While hard to prove, this makes sense. Brain function is the result of many polarizations and depolarizations taking place between neurons. And, the coordinated electrochemical polarization and depolarization of the heart is what causes the heart to beat regularly. Disruption of either, or both, could certainly be the cause of death in victims of direct lightning strikes.