A strong electric shock can often cause painful muscle spasms severe enough to dislocate joints or even to break bones.

The loss of muscle control is the reason that a person may be unable to release themselves from the electrical source; if this happens at a height as on a power line they can be thrown off.

[8] Following an electrical injury from household current, if a person has no symptoms, no underlying heart problems, and is not pregnant further testing is not required.

For most cases of high-energy electrical trauma, the Joule heating in the deeper tissues along the extremity will reach damaging temperatures in a few seconds.

Mechanism of cardiac arrhythmias induced by electricity is not fully understood, but various biopsies have shown arrhythmogenic foci in patchy myocardial fibrosis which contained increased amount of Na+ and K+ pumps, possibly associated with transient and localized changes in sodium-potassium transport as well as their concentrations, resulting in changes in membrane potential.

[citation needed] Electric shock which does not lead to death has been shown to cause neuropathy in some cases at the site where the current entered the body.

[10] The neurologic symptoms of electrical injury may occur immediately, which traditionally have a higher likelihood for healing, though they may also be delayed by days to years.

[10] Symptoms may include:[10] OSHA found that up to 80 percent of its electrical injuries involve thermal burns due to arcing faults.

[21] The protection offered by the skin is lowered by perspiration, and this is accelerated if electricity causes muscles to contract above the let-go threshold for a sustained period of time.

[25] Resistance measurements made at low voltage using a standard ohmmeter do not accurately represent the impedance of human skin over a significant range of conditions.

The earliest usage of the term "electrocution" cited by the Oxford English Dictionary was an 1889 newspaper reference to the method of execution then being considered.

According to the Guinness Book of World Records, seventeen-year-old Brian Latasa survived a 230,000 volt shock on the tower of an ultra-high voltage line in Griffith Park, Los Angeles on November 9, 1967.

[33] A news report of the event stated that he was "jolted through the air, and landed across the line", and though rescued by firemen, he sustained burns over 40% of his body and was completely paralyzed except for his eyelids.

[34] The shock with the highest voltage reported survived was that of Harry F. McGrew, who came in contact with a 340,000 volt transmission line in Huntington Canyon, Utah.

Research shows that for very short electric pulse durations below 100 μs the threshold curve converges into a constant charge criterion independent of peak current or RMS values.

Electrical devices have non-conductive insulation preventing contact with energized wires or parts, or may have conductive metal enclosures connected to earth ground so that users will not be exposed to dangerous voltage.

With proper training and equipment, live-line maintenance is routinely safely carried out on electrical transmission lines energized at hundreds of thousands of volts.

[41] In Nigeria, analysis of Nigerian Electricity Regulatory Commission data found 126 recorded electrocution deaths and 68 serious injuries in 2020 and the first half of 2021.

[43] Even without visible burns, electric shock survivors may be faced with long-term muscular pain and discomfort, exhaustion, headache, problems with peripheral nerve conduction and sensation, inadequate balance and coordination, among other symptoms.

Electrical injury can lead to problems with neurocognitive function, affecting speed of mental processing, attention, concentration, and memory.

However devices such as a joy buzzer and most other machines in amusement parks today only use vibration that feels somewhat like an electric shock to someone not expecting it.

One type is a conductive energy device (CED), an electroshock gun popularly known by the brand name "Taser", which fires projectiles that administer the shock through a thin, flexible wire.

Electric shocks are used as a method of torture, since the received voltage and current can be controlled with precision and used to cause pain and fear without always visibly harming the victim's body.

[50] Amnesty International published a statement that Russian military forces in Chechnya tortured local women with electric shocks by attaching wires onto their breasts.

[51] The use of electric shocks to torture political prisoners of the Brazilian military dictatorship (1964 - 1985) is detailed in the final report of the National Truth Commission, published December 10, 2014.

The parrilla was commonly used at Villa Grimaldi, a prison complex maintained by Dirección de Inteligencia Nacional, a part of the Pinochet regime.

[55] Francisco Tenório Júnior (known as Tenorinho), a Brazilian piano player, was subjected to the parrilla during the military dictatorship in Brazil.

[57][58][59] Advocates for the mentally ill and some psychiatrists such as Thomas Szasz have asserted that electroconvulsive therapy (ECT) is torture when used without a bona fide medical benefit against recalcitrant or non-responsive patients.

Although some original proponents of the electric chair considered it to be a more humane execution method than hanging, shooting, poison gassing, etc., it has now generally been replaced by lethal injections in states that practice capital punishment.

Modern reporting has claimed that it sometimes takes several shocks to be lethal, and that the condemned person may actually catch fire before death.