Electric shock: Effects on body, symptoms, first aid, and more

When an electric current touches or flows through the body, this is known as an electric shock. It can happen wherever there is live electricity. The effects of an electric shock range from none at all to severe injury and death.

Approximately 5% of burn unit admissions in the United States are due to electrical injuries. Anyone who receives a high voltage shock or an electrical burn should seek medical advice immediately.

This article looks at the symptoms of an electric shock, provides advice on first aid procedures, and explains when to seek medical help.

What is an electric shock?

An electric shock occurs when an electric current passes from a live outlet to part of the body.

Electric shocks can result from contact with:

• faulty electrical appliances or machinery
• household wiring
• electrical power lines
• lightning
• electricity outlets

The domestic electricity running through a typical U.S. household is 110 volts (V), with some appliances needing 240 V. Industrial and power lines may carry more than 100,000 V.

High voltage currents of 500 V and more can cause deep burns, while low voltage currents consisting of 110–120 V can result in muscle spasms.

A person can get an electric shock through contact with an electric current from a small household appliance, wall outlet, or extension cord. These shocks rarely cause severe trauma or complications.

About half of electrical injuries occur in the workplace. High risk occupations for nonfatal electrocutions include:

• construction
• leisure and hospitality
• education and health services
• accommodation and food services
• manufacturing

Several factors can affect the severity of electric shock injuries, including:

• the intensity of the current
• the type of current — alternating current (AC) or direct current (DC)
• which part of the body the current reaches
• how long a person has exposure to the current
• resistance to the current

The let-go threshold

The let-go threshold is the level where a person’s muscles contract, meaning that they are unable to let go of the electrical source until someone safely removes it. This table shows the body’s response to different intensities of current, using milliamps (mA) as the measurement:

Current (mA)Response0.2–2an electrical sensation1–2+a painful shock3–5let-go threshold for children6–10minimum let-go threshold for adults10–20possible seizure at the contact point22inability to let go, for 99% of adults20–50possible seizures50–100possible life threatening heart rhythms

First aid

Minor electric shocks, such as those from small household appliances, do not typically need medical treatment. However, a person should see a doctor if they have experienced electrocution.

If someone has received a high voltage shock, it is important to call 911 right away.

If a person experiences a serious electric shock, the Centers for Disease Control and Prevention (CDC) give the following advice for how to respond as a bystander:

• Do not touch the person, as they may be in contact with the electrical source.
• Call 911 or have someone else call 911.
• If it is safe to do so, turn off the source of electricity. If it is not safe, use a nonconducting object made of wood, cardboard, or plastic to move the source away.
• After removing the electrical source, check the person for a pulse, and determine whether they are breathing. If the person has no pulse, begin CPR immediately.
• If the person is faint or pale, lay them down with their head lower than their body and elevate their legs.
• A person should neither touch any burns nor remove burned clothing.

A person can perform CPR by:

1. Administering compressions: Place one hand on top of the other in the middle of the chest. Using body weight, push down hard and fast to administer compressions that are 2 inches deep. The aim is to deliver 100–120 compressions per 60 seconds.
2. Delivering rescue breaths: First, make sure that the person’s mouth is clear. Then, tilt their head back, lift their chin, pinch their nose closed, and blow into their mouth to make their chest rise. Perform two rescue breaths and continue administering compressions.
3. Repeating the process: It is important to carry on until help arrives or the person begins breathing.

Diagnosis

At the emergency department, the doctor will perform a thorough physical exam to assess potential external and internal damage. They will likely order tests, which may include:

• electrocardiogram (EKG) to monitor the heart’s rhythm
• pregnancy test, which is for pregnant people only, to assess any impact on the developing baby
• CT scan to check the health of the brain, spine, and chest
• blood tests to check for rhabdomyolysis

A medical professional will only order CT scans and blood tests if they suspect internal injury.

Not every person who experiences an electric shock needs to visit the emergency department. People can follow this advice:

• Call 911 if a person experiences a high voltage shock, which is one of 500 V or more. These voltages can cause deep burns that require immediate attention.
• Go to the emergency department following a low voltage shock that results in a burn. It is important not to try to treat the burn at home.
• If a person experiences a low voltage shock with no burn injury, they should visit a doctor to ensure that no damage has occurred.

Outlook

Electric shocks can cause injuries that are not always visible. Depending on how high the voltage was, the injury may be fatal. However, if a person survives the initial electrocution, they should seek medical attention to ensure that no injuries have occurred.

Anyone who thinks that an individual has had a severe electric shock should call 911 right away.

Even after a minor shock, a person should see a doctor.

Summary

Electric shocks range from minor to severe, as do the injuries they can cause. Many electric shocks occur in the home, so it is important to check household appliances regularly for signs of damage.

People working in proximity to the installation of electrical systems should take particular care and always follow safety regulations.

If a person has experienced a severe electric shock, a bystander should call 911 and administer first aid if it is safe to do so.