Direct lightning strikes can impact the cardiovascular system, causing depolarization of the heart, leading to arrhythmias or complete cardiac arrest.
According to experts, in addition to the thermal characteristics that cause burns, lightning can cause cardiac arrest and respiratory failure due to its electrical properties. In fact, the human body generates a type of natural electrical impulse, created when electrical charges pass through cells. The movement of these electrical signals allows information to travel throughout the nervous system, brain, and nerve pathways across the body. Essentially, electrical impulses inform the brain of what actions to take in specific situations.
When lightning strikes the nervous system, it directly damages cells, causing temporary paralysis and causing arteries and blood vessels in the brain to rupture. The electrical discharge from lightning can also severely damage the heart and vascular system. The current from a lightning strike can cause the heart to beat faster or slower than normal, affecting blood flow throughout the body. The heart muscle can also be bruised, particularly in the aorta—the largest artery in the body.
Cardiac arrest often occurs in individuals who are struck directly by lightning, which is the most dangerous type of lightning strike. Victims are often in open areas, which allows the greatest amount of electricity to pass through their bodies compared to other types of lightning. Unlike a direct strike, there is also side flash lightning (where lightning strikes a tall object and part of the current travels to the victim), ground current lightning, and transmission line lightning.
According to Dr. Jack Keys from the Department of Basic Medical Sciences at the University of Oregon, being near a lightning strike can also create current within the body. This leads to depolarization of the heart, causing the heart rhythm (which is generated by resistance) to become chaotic or stop completely.
Direct lightning strikes can lead to cardiac arrest.
Because lightning disrupts the nervous and cardiovascular systems, it has widespread effects on the rest of the body, including the respiratory system. For instance, a heart that does not pump blood regularly will struggle to manage the blood received from the lungs. This causes blood to back up, increasing pressure in the blood vessels and pushing blood into the lung’s air sacs, leading to pulmonary edema. Additionally, lightning can cause the respiratory system to shut down.
These powerful effects can lead to long-term damage. Survivors of lightning strikes may experience lifelong movement disorders and nerve damage, cataracts, damage to the optic nerve, facial nerve paralysis, hearing loss, frequent dizziness, and tinnitus. In fact, around 50-80% of lightning strike victims have experienced eardrum rupture.
Physical damage to the body, particularly the nervous system, can lead to long-term cognitive issues, including depression, lack of concentration, forgetfulness, slow reaction times, difficulty processing information, and social isolation, as reported by the National Weather Service in the United States.
Due to these short-term and long-term effects, experts recommend paying attention to weather conditions to reduce the risk of being struck by lightning. Statistics show that the likelihood of an individual being struck by lightning is one in 16,000. Men are five times more likely to be struck by lightning than women, accounting for about 85% of lightning-related fatalities. Individuals working outdoors are also at higher risk of lightning strikes. Approximately one-third of lightning-related deaths occur on farms.
