Voltage vs. Current: Understanding the Difference
Voltage, electrical pressure, is the potential difference pushing electrical charges. Sufficient voltage is needed to overcome skin resistance and allow current flow. The current—flow of electrons—directly damages tissues. Higher voltage increases dangerous current likelihood. Even lower voltages can be lethal if resistance is low, like with wet skin.
The Path of Least Resistance
Electricity follows the path of least resistance through the body, impacting injury severity. A current crossing the chest is dangerous as it can affect the heart.
Effects of Electric Current on the Body's Systems
Once current penetrates the skin, it can cause various effects.
Cardiovascular system
- Cardiac Arrest: Electrical current can disrupt the heart's electrical signals, leading to uncoordinated twitching (ventricular fibrillation). This is a major death cause.
- Arrhythmias: Survivors may have long-term heart rhythm problems.
Nervous system
- Neurological Damage: The nervous system is sensitive to electricity, which can damage nerves and cause numbness, weakness, and paralysis.
- Cognitive and Psychological Effects: Shocks affecting the head can cause loss of consciousness, memory issues, seizures, and cognitive problems. Anxiety and PTSD are also common.
Muscular system
- Muscle Contractions: Current can cause powerful, involuntary muscle contractions. This can cause a person to grip the source tighter.
Integumentary system (Skin)
- Electrical Burns: Burns occur at entry and exit points due to heat. High-voltage burns can cause explosive exit wounds; low-voltage burns may look minor but hide internal damage.
Other factors influencing severity
Several factors besides current path and magnitude affect the outcome.
- Duration of Contact: Longer exposure leads to greater damage. Even low voltage can be lethal with sustained contact.
- Moisture: Wet skin significantly lowers resistance, allowing higher current to flow, making injuries in wet conditions hazardous.
- Voltage Type (AC vs. DC): Alternating current (AC) is generally more dangerous than direct current (DC) of equal voltage.
Comparison of Low-Voltage and High-Voltage Injuries
| Feature | Low-Voltage (<500V) | High-Voltage (>500V) |
|---|---|---|
| Primary Cause of Death | Often ventricular fibrillation (disrupted heart rhythm). | Immediate, severe burns and internal organ destruction. |
| Appearance of Burns | Can be subtle externally, masking extensive internal damage. | Severe, deep, and charred burns at entry and exit points are common. |
| Muscle Response | May cause muscles to contract, freezing the victim to the source. | Can cause explosive muscular contractions that throw the victim from the source. |
| Arc Flash Risk | Generally low, though possible in certain conditions. | High risk of arc flash burns, which can happen without direct contact. |
| Internal Damage | Potential for multi-system trauma, especially affecting the heart and nerves. | Widespread, devastating internal damage due to massive heat generation. |
Safety and First Aid
Electrical injuries are medical emergencies. If someone is shocked, prioritize your safety: “Look first, don't touch”.
- Assess the Scene: Ensure safety before approaching. Check if they're still in contact with the source.
- Turn Off the Power: If possible, shut off the power at the breaker. If not, use a dry, non-conductive object to move the person away.
- Call for Help: Immediately call 911 or emergency services.
- Administer CPR: Once safe, check for breathing and pulse. If absent and you're trained, begin CPR.
- Treat for Shock and Burns: Lay the person down and cover burns with a sterile dressing. Avoid ice or water on burns.
- Seek Medical Evaluation: Even if they appear fine, all electrical shock victims need medical attention due to potential unseen internal damage. For more detailed first aid information, refer to {Link: Mayo Clinic https://www.mayoclinic.org/first-aid/first-aid-electrical-shock/basics/art-20056695}.
Conclusion
While voltage provides the force, current flowing through the body causes damage during an electric shock. Severity depends on factors like voltage, current, duration, and the current's path. Understanding these risks is crucial for safety and response. Always respect electricity's power, including from low-voltage sources.
