The degree of electricity-induced injury is dependent on:

• The amount of electrical energy that is delivered
• The resistance that is encountered
• The type of current
• The current pathway
• The duration of contact

Contact with alternating current (AC) is more likely to cause sustained muscular contraction than contact with direct current (DC). This sustained muscular contraction may prevent the victim from releasing the electrical source, increasing the duration of contact and the amount of electrical energy that is delivered.

The resistance that is encountered is dependent on the body tissue that is traversed by the electrical current. Generally, tissues with high fluid electrolyte concentrations will conduct electricity the best. Bone is the most resistant tissue to electrical flow. Skin impedes electrical current, but resistance is dependent on the skin's thickness and moisture. Wet skin can reduce the contact resistance of the body.

The degree of electricity-induced injury is also determined by which tissues are in the current pathway. Electrical current that passes through the head or thorax produces the most serious injuries including fatal arrhythmia, direct cardiac damage, respiratory arrest, direct brain injury, and paralysis.