Lightning is extraordinarily dangerous, carrying roughly 300 million volts and 30,000 amps of current, and heating the surrounding air to 50,000 degrees Fahrenheit, five times hotter than the surface of the sun. It kills about 20 people per year in the United States and injures hundreds more. But the full picture of lightning’s danger goes beyond fatalities. Survivors frequently live with chronic pain, memory loss, and personality changes that last years or a lifetime.
Five Ways Lightning Can Strike You
Most people picture a direct hit when they think of a lightning strike, but that’s actually the least common way people are injured. The National Weather Service identifies five distinct mechanisms, and understanding them helps explain why lightning is dangerous even when it doesn’t hit you directly.
Ground current is the number one cause of lightning deaths and injuries. When lightning hits a tree, pole, or the ground itself, much of the energy spreads outward along the surface. Anyone standing nearby can have that current travel up one leg and down the other. Because ground current covers a wide area, it affects far more people than direct strikes do.
Side flash happens when lightning hits a tall object and part of the current jumps to a person standing within a foot or two. This is exactly why sheltering under a tree is so dangerous. The tree attracts the strike, and your body provides a shorter path for some of the energy to reach the ground.
Conduction is the main way people get hurt indoors. Lightning travels through metal wires, plumbing, and other conductive surfaces. Anything plugged into a wall outlet, any water faucet, corded phone, or even metal window frames can carry the current to you. Metal doesn’t attract lightning, but once lightning enters a structure, metal gives it a highway.
Direct strikes are relatively rare but the most potentially deadly. They typically happen to people in open areas with no shelter. When current passes through the body, it travels through the cardiovascular and nervous systems. Some of the energy also moves along the skin’s surface in what’s called flashover, which is partly why direct strikes aren’t always fatal.
Streamers are the least well-known mechanism. As a lightning bolt reaches toward the ground, multiple upward-reaching channels of electricity rise to meet it. Only one completes the connection, but all of them discharge energy. If you happen to be part of one of those incomplete channels, you can still be killed or seriously injured even though the main bolt struck somewhere else.
What Lightning Does to the Human Body
The most immediate threat is cardiac arrest. Lightning can stop the heart or throw it into a chaotic, ineffective rhythm. When the heart stops or beats erratically, breathing often stops too. This is why CPR from a bystander can be the difference between life and death for a strike victim.
The nervous system takes a heavy hit. Lightning can cause seizures, loss of consciousness, and coma. Even when a person wakes up, they often can’t remember what happened. Confusion, slow thinking, and difficulty concentrating are common in the days and weeks that follow. Both legs frequently become temporarily paralyzed and numb, a condition called keraunoparalysis, which can be terrifying but usually resolves.
Skin injuries vary widely. Some victims show no visible marks at all. Others develop distinctive feathering, branching patterns on the skin (known as Lichtenberg figures) where the current traveled. Some have clusters of tiny pinpoint burns or streaks where sweat was flash-heated into steam. These skin signs can look dramatic but are often superficial compared to the internal damage.
Long-Term Effects Survivors Live With
Surviving a lightning strike doesn’t mean walking away healthy. The National Weather Service maintains a collection of survivor accounts, and the same symptoms come up again and again: chronic pain, memory loss, depression, headaches, joint pain, difficulty concentrating, ringing in the ears, and anger issues. Many survivors also report PTSD, heightened startle responses, and an inability to sleep normally.
Nerve damage outside the brain and spinal cord is common too. Numbness, tingling, and weakness can develop from damaged peripheral nerves, and these symptoms may persist indefinitely. Some survivors describe digestive problems, vision changes, and hypersensitive hearing. Personality changes can be permanent, affecting relationships and the ability to work. One survivor described “near total inability to sleep, heart palpitations, headaches, nausea, dizziness, fatigue, memory problems, inability to concentrate, loud ringing in my ears.” These accounts are not outliers. They represent a pattern that makes lightning’s true danger much greater than a simple survival statistic would suggest.
You’re Not Safe Indoors by Default
A solid building with wiring and plumbing is the safest place during a thunderstorm, but “indoors” doesn’t mean “immune.” Lightning can travel through a building’s plumbing, so you should avoid bathing, showering, or washing dishes during a storm. Plastic pipes reduce the risk somewhat compared to metal plumbing, but any contact with running water carries some danger.
Corded phones are not safe during a thunderstorm. (Cell phones and cordless phones are fine since they’re not connected to wiring.) Anything plugged into an electrical outlet can conduct a strike’s energy. Concrete floors and walls can also be hazardous because they often contain metal rebar or wire mesh that lightning can travel through.
How Close Is Too Close
Lightning can strike well ahead of or behind a storm’s rain. Thunder is typically audible from about 10 miles away, which means if you can hear thunder at all, you are within striking distance. There is no safe place outside when thunderstorms are in the area.
The current safety guideline from the National Weather Service is straightforward: “When thunder roars, go indoors.” This replaces older, more complicated rules. Get inside a substantial building or a hard-topped vehicle as soon as you hear thunder or see threatening skies. Once the storm passes, wait at least 30 minutes after the last thunder or lightning flash before going back outside. Many lightning deaths happen because people return outdoors too soon, during a storm’s deceptive lull.
Planning ahead matters more than reacting in the moment. If you’re heading to an outdoor event, a hike, or a day at the beach, know where the nearest safe shelter is before the sky changes. Lightning gives less warning than most people assume, and the range of ways it can reach you, from ground current to conduction through plumbing, makes it a threat that’s easy to underestimate.