I saw a post on a student struck to death by lightning and saw several comments but failed to see how lightning affects humans. However, from my little research, these are my findings and please feel free to add yours.

A lightning strike or lightning bolt is an electric discharge between the atmosphere and an Earth-bound object.[citation needed] They mostly originate in a cumulonimbus cloud and terminate on the ground, called cloud to ground (CG) lightning.

Lightning strikes can injure humans in several different ways:

Lightning strikes can produce severe injuries, and have a mortality rate of between 10% and 30%, with up to 80% of survivors sustaining long-term injuries. These severe injuries are not usually caused by thermal burns, since the current is too brief to greatly heat up tissues; instead, nerves and muscles may be directly damaged by the high voltage producing holes in their cell membranes, a process called electroporation.

In a direct strike, the electrical currents in the flash channel pass directly through the victim. The relatively high voltage drop around poorer electrical conductors (such as a human being), causes the surrounding air to ionize and break down, and the external flashover diverts most of the main discharge current so that it passes "around" the body, reducing injury.

Metallic objects in contact with the skin may "concentrate" the lightning's energy, given it is a better natural conductor and the preferred pathway, resulting in more serious injuries, such as burns from molten or evaporating metal. At least two cases have been reported where a strike victim wearing an iPod suffered more serious injuries as a result.

However, during a flash, the current flowing through the channel and around the body will generate large electromagnetic fields, which may induce electrical transients (surges) within the nervous system or pacemaker of the heart, upsetting normal operations. This effect might explain cases where cardiac arrest or seizures followed a lightning strike that produced no external injuries. It may also point to the victim not being directly struck at all, but just being very close to the strike termination.

Another effect of lightning on bystanders is to their hearing. The resulting shock wave of thunder can damage the ears. Also, electrical interference to telephones or headphones may result in damaging acoustic noise.


Source:
https://en.wikipedia.org/wiki/Lightning_strike