According to the Occupational Safety & Health Administration, electricity is dangerous because it can cause burns, nerve damage, cardiac arrest and death. Alliant Engery also notes that the majority of the human body is composed of water, which makes it a good conductor of electricity.
OSHA states that injuries from an electrical shock vary based on the amount of current passing through the body and the length of time a person is exposed to electricity. At a low current of one milliampere, a person feels a tingling sensation, but the electricity is unlikely to cause injury. However, as the current increases, electrical shock becomes more painful, causes muscle contractions and damages internal organs, including paralysis of the heart and lungs.