Fulguration is the medical term used to describe an injury resulting from a lightning strike. This trauma differs significantly from a typical electrical shock due to the magnitude and speed of the discharge. A single lightning bolt can carry up to 30 million volts and a current reaching 110,000 amperes. This immense power is delivered in an extremely short duration, often measured in microseconds, which influences the patterns of injury observed.
How Lightning Strikes Injure the Body
A direct strike is the rarest mechanism, accounting for approximately 5% of cases. The electrical current’s interaction with the body’s tissues is the primary driver of internal damage, causing rapid heating and the physical disruption of cell membranes.
The most frequent mechanism of injury, making up 40% to 50% of cases, is the ground current effect. This occurs when lightning strikes the earth nearby, and the current travels through the ground, entering a person through one contact point and exiting through another. This mechanism is responsible for the majority of lightning-related deaths and injuries.
Another common injury mechanism is the side flash, accounting for about 30% of cases. This happens when lightning strikes a taller object, and a portion of the current jumps through the air to a nearby person. Injury can also occur through conduction, which involves touching an object that has been struck, such as a fence. The injury pattern is highly dependent on the current’s path and the duration of exposure.
Immediate Life-Threatening Effects on the Heart and Lungs
The most immediate cause of death following a lightning strike is cardiorespiratory arrest. The instantaneous electrical charge can completely depolarize the heart muscle, typically resulting in asystole—a temporary cessation of all electrical activity. This differs from the ventricular fibrillation often seen in industrial electrical shocks.
In many cases, the heart’s natural pacemaker cells may spontaneously restart the cardiac rhythm shortly after the strike. However, the respiratory system often remains paralyzed because the current passes near or through the brainstem, which controls involuntary breathing. This respiratory paralysis can be prolonged, and the resulting lack of oxygen will eventually cause a secondary, irreversible cardiac arrest.
Aggressive and prolonged cardiopulmonary resuscitation is highly recommended, even for victims who appear deceased. This approach is guided by the understanding that the heart may have a higher chance of spontaneous recovery, but sustained ventilation is necessary to prevent fatal hypoxia. The high percentage of immediate deaths are generally attributed to these initial arrhythmias or respiratory failure.
External Thermal Damage and Physical Trauma
External injuries from a lightning strike can be dramatic, though often less severe than expected. The skin’s high resistance, especially when dry, causes the current to travel over the surface in a phenomenon called flashover, which limits internal damage in many survivors.
Thermal damage often manifests as flash burns, which are superficial and caused by the rapid vaporization of sweat and moisture on the skin’s surface into steam. This superheated steam can cause first and second-degree burns. Unlike industrial electrical injuries, lightning typically does not cause deep tissue burns, though it can ignite clothing.
A characteristic sign of a lightning strike is the appearance of Lichtenberg figures, which are transient, fern-like reddish patterns on the skin. These markings are not true thermal burns and are typically painless. They usually fade completely within 24 to 48 hours without leaving a scar.
Physical trauma is also a significant concern, often resulting from the shockwave created by the rapid heating and expansion of air around the lightning channel. This explosive force can throw a person a great distance, causing blunt force trauma, fractures, and internal injuries.
Neurological and Sensory System Consequences
The nervous system is particularly vulnerable to electrical current and is the site of many lasting effects of a lightning strike. The electrical discharge can disrupt the central, peripheral, and autonomic nervous systems, leading to a wide spectrum of issues.
A temporary paralysis known as Keraunoparalysis is a common immediate neurological presentation. This condition typically affects the lower limbs, causing weakness, numbness, and a pale, cool appearance in the extremities. It is believed to be caused by temporary blood vessel spasm and usually resolves spontaneously within hours to days.
Long-term neurological complications can include persistent cognitive impairment, such as memory loss, difficulty concentrating, and slowed thinking. Survivors may also experience chronic neuropathic pain, headaches, and complex regional pain syndrome (CRPS).
Sensory organs are highly susceptible to the blast wave and electrical energy. Ruptured eardrums (tympanic membrane rupture) are observed in victims due to the explosive concussive force. Ocular injuries are common, with the delayed formation of cataracts being a notable long-term consequence.