Electric shock can injure nearly every organ system in the body, from the skin down to the heart, nerves, muscles, and kidneys. The specific injuries depend on the voltage, the type of current, how long contact lasted, and the path the electricity traveled through the body. Injuries are broadly divided into low-voltage (under 1,000 volts, like household current) and high-voltage (1,000 volts or more, like power lines). High-voltage injuries carry mortality rates between 5% and 30%, while low-voltage injuries are fatal in fewer than 1% to 3% of cases.
Burns and Skin Damage
Burns are the most visible injury from electric shock, and they come in several forms. A true conductive burn happens when current flows directly through tissue, generating heat from the inside out. These burns are deceptive: the entry and exit wounds on the skin may look small and harmless, but underneath, the damage can extend deep into muscle, blood vessels, and bone. Fingers, hands, forearms, feet, and lower legs are especially vulnerable because their smaller cross-section concentrates the current, sometimes destroying tissue completely.
Arc burns occur when electricity jumps across a gap between two conductors, producing temperatures hot enough to ignite clothing and cause conventional thermal burns on top of the electrical injury. Flash burns, caused by the intense heat radiating from an electrical arc, can scorch exposed skin without the current ever entering the body. In high-voltage or lightning injuries, a distinctive fern-like pattern called a Lichtenberg figure sometimes appears on the skin. This branching mark is caused by a positive electrical discharge that damages small blood vessels near the surface, allowing red blood cells to leak into surrounding tissue. These patterns are temporary and unique to lightning or very high-voltage events.
Heart and Circulatory Injuries
The heart is one of the most vulnerable organs during electric shock. Current passing through the chest can disrupt the heart’s electrical system, triggering abnormal rhythms, conduction problems, or direct damage to heart muscle. The most dangerous of these is ventricular fibrillation, where the heart quivers chaotically instead of pumping blood. This is the most common cause of death from electrical injury, and it typically happens immediately if the current reaches the heart during a critical moment in its beat cycle.
In a study of 480 patients seen in emergency departments after electrical accidents, the most frequently detected rhythm abnormalities were an unusually slow heart rate (about 10% of patients) and an unusually fast heart rate (about 4%). Other findings included irregular heartbeats, brief episodes of dangerous rhythms, and conduction blockages where electrical signals within the heart are delayed or interrupted. Most of these arrhythmias appear right away, which is why an initial heart tracing is considered the single most useful tool for predicting whether serious cardiac complications will follow.
Nerve and Brain Damage
Neurological injuries are among the most common consequences of electric shock, affecting the brain, spinal cord, or peripheral nerves in up to 70% of people who experience low-voltage injuries. These problems can show up immediately or develop weeks to months later, which makes them particularly difficult to anticipate.
Immediate symptoms often include numbness, tingling, weakness, or pain along the path the current traveled. The mechanisms behind nerve damage are varied: direct heat injury to nerve tissue, spasm of blood vessels cutting off oxygen supply, and overactivation of the body’s stress response system. In some cases, the vascular damage caused by electrical injury can trigger a stroke. One documented case involved a man who developed right-sided weakness and loss of speech five weeks after a low-voltage shock, with brain imaging confirming a stroke caused by a blocked artery.
Over the longer term, survivors of electrical injury frequently report pain, peripheral nerve symptoms, and problems with memory and concentration that persist well beyond the initial recovery period.
Muscle Breakdown and Kidney Failure
Electric current causes muscles to contract violently, and high-voltage current can directly destroy muscle fibers. When large amounts of muscle tissue break down, a condition called rhabdomyolysis develops. Damaged muscle cells release their contents into the bloodstream, including a protein called myoglobin that can clog the kidneys and lead to acute kidney failure.
This chain of events is especially common with high-voltage injuries. The muscle destruction also causes swelling within the tight compartments of the arms and legs. As pressure builds inside these compartments, it can compress blood vessels and cut off circulation to the tissue below, creating a dangerous cycle: reduced blood flow causes further tissue death, which causes more swelling. This is called compartment syndrome, and it requires emergency surgical intervention to relieve the pressure. High-voltage injuries carry significantly higher rates of compartment syndrome, rhabdomyolysis, kidney failure, and limb amputation compared to low-voltage injuries.
Lung and Internal Organ Damage
When electric current passes through the chest, the lungs can sustain both direct and indirect damage. The most common finding is pulmonary edema, where fluid accumulates in the lungs. This usually happens because the heart fails to pump effectively after the shock, causing blood to back up into the lung tissue. The lungs become heavy, waterlogged, and overinflated. In rarer cases, lung injury can occur independently of heart failure through mechanisms that aren’t fully understood but appear to involve stimulation of the brain’s control centers for blood vessel tone.
High-voltage injuries have also been documented to cause hemorrhaging in the kidneys and, in extreme cases, perforation of major blood vessels like the aorta. The path the current takes through the body largely determines which internal organs are affected. Current traveling from hand to hand crosses the chest and puts the heart and lungs at greatest risk. Current traveling from hand to foot may pass through abdominal organs. When the entry or exit wound is on the chest or abdomen, the risk of visceral damage increases substantially.
Delayed and Long-Term Effects
Some injuries from electric shock don’t become apparent until weeks or months later. Cataracts are a well-documented delayed complication, particularly when the current contacts the head or passes near the eyes. In studies of severe electrical burn patients, roughly 6% developed cataracts within the first year, typically appearing between one and twelve months after the injury, with a smaller number developing them within three years. The risk is highest when there’s a contact point on the skull or near the eye.
Chronic pain syndromes, ongoing nerve dysfunction, and cognitive difficulties represent another category of delayed effects. Patients seen in occupational medicine clinics after electrical accidents sometimes had no severe acute injury but gradually developed persistent pain, peripheral nerve symptoms, or impairments in memory and concentration. These long-term neurological consequences can appear even after relatively low-voltage exposures, making follow-up important for anyone who has experienced a significant electric shock.
How Voltage and Current Path Shape the Injury
Not all electric shocks produce the same pattern of injury. Two factors matter most: how much current flows through the body and what path it takes. Voltage drives the current, but the body’s resistance at the point of contact determines how much current actually enters. Dry, calloused skin has much higher resistance than wet or broken skin, which is why shocks in wet environments tend to be more dangerous at the same voltage.
Low-voltage household current (under 1,000 volts) is more likely to cause prolonged muscle contraction, or tetany, which can lock a person’s hand onto the source and extend the duration of contact. This extended exposure increases the total energy delivered to the body. High-voltage current, by contrast, often causes a single violent muscle contraction that throws the person away from the source but inflicts massive deep tissue destruction in the process. In the United States, 130 workers died from electrical exposure on the job in 2024, a reminder that even with modern safety standards, electrical injuries remain a serious occupational hazard.