An electric shock can occur upon contact of a human's body with any source of voltage high enough to cause sufficient current flow through the muscles or hair. The minimum current a human can feel is thought to be about 1 milliampere (mA).The current may cause tissue damage or fibrillation if it is sufficiently high. Death caused by an electric shock is referred to as electrocution.
The perception of electric shock can be different depending on the voltage, duration, current, path taken, frequency, etc. Current entering the hand has a threshold of perception of about 5 to 10 mA (milliampere) for DC and about 1 to 10 mA for AC at 60 Hz. Shock perception declines with increasing frequency, ultimately disappearing at frequencies above 15-20 kHz.
Heating due to resistance can cause extensive and deep burns. Voltage levels of (> 500 to 1000 V) shocks tend to cause internal burns due to the large energy (which is proportional to the duration multiplie