I know that many people would answer the question posed in the title by saying, “Because it can kill you, dummy!” and they wouldn’t be incorrect. It is true that an electric shock, if powerful enough, can kill you.
But what exactly is it about electricity that makes it potentially lethal? And not just to people, but also animals, birds and other living things. Why does experiencing a strong enough electric shock mean grievous injuries or even death to those victims?
Electricity inside the body
It’s funny how electricity is considered to be a big threat and we are told to stay clear of ‘it’ at all times, yet our own bodies only function because there’s electricity inside them, or at least, electrical signals are doing their thing.
The elements present in our bodies, such as sodium, calcium, potassium and magnesium, have a specific electric charge. Almost all of our bodily cells use these charged elements, called ions, to generate small amounts of electricity.
There are so many examples of how electric currents generated inside the body help it to run. For instance, in order for the heart to pump blood, cells must generate electric currents that allow the muscles of the heart to contract at precisely the right time. We can even measure the value of these electric currents using a device called an electrocardiogram (ECG). Does the following picture ring a bell?
This is an ECG report, i.e., a reading of the electric current flowing through your heart.
Of course, electric signals flow through our nerves all the time. They provide us with the power of muscle control, which helps us to sit up/down, stand up, walk around, grab things, throw things, play video games… you get the idea, right? In short, they let us do everything.
There are electrical synapses that link two adjacent neurons and help pass nerve impulses at lightning speed. The entire autonomous nervous system only works because there are just the right amount of such synapses that have electrical impulses flowing through them.
So, it’s pretty clear that our bodies depend on electricity to function properly, which is why it is generated inside the body. However, the power of those electrical signals are nothing compared to the currents that flow through thick wires and large electrical appliances.
How exactly do electric shocks harm people?
The human body is not a perfect conductor of electricity; as such, when it encounters electricity from an outside source, it offers resistance to the flow of electricity through itself. And, as you might know, resistance to the flow of current generates heat – a lot of it (if the electric current is powerful enough). So, if one comes in contact with a power line with amperage, they run the risk of sustaining electric burns.
This is not just harmful to the exterior skin; such burns can run deep and damage tissue, which can cause gangrene and necrosis. Unfortunately, that’s why limbs sometimes need to be amputated if one falls victim to a high-voltage mishap.
The heart is an electrically well-tuned machine, which means that it relies on just the right amount of electric current to keep pumping. However, when you’re electrocuted, all of that balance and control go haywire.
Electrocution can potentially interrupt or even completely stop those small electrical signals (that tell the heart to pump). This can cause the heart to beat incorrectly, or even stop beating altogether. Obviously, we all know that’s not a situation one wants to be in, if they want to survive.
However, not all electric shocks cause the heart to stop. It must be noted that the extent and type of damage caused by electric shocks hugely depend on which part of the body is hit, since electricity always seeks out the quickest path to reach the ground.
Loss of muscle control
Electrocution also causes muscle contractions. Since our muscle system relies on small electric currents to work properly, it doesn’t appreciate a sudden and large influx of electricity. When that happens, one can lose control over their muscles, or experience spasms and muscle contractions. In the in worst-case scenario, you may experience complete paralysis. That’s why one can end up tightening their grip on the wire when they are electrocuted, rather than doing the opposite.
A sudden loss of muscle control can also cause the victim to fall, which can be fatal if they hit solid ground at an awkward angle. Many electrocution victims suffer grievous bodily injuries due to such falls and accidents, which result from a loss of muscle control after experiencing an electric shock.