The sight of blood. Crossing paths with a famous person. Anxiety on your wedding day. These are typical scenarios in movies, or even real life, where the outcome is someone fainting. But what exactly is going on in our body that causes us to lose consciousness?
Fainting, also known as syncope, occurs when the brain does not get enough oxygen. Low oxygen to the brain can be due to a sudden drop in blood pressure. The nervous system signals the heart to slow down and blood vessels to widen, leading to low blood pressure. This sudden drop in pressure can be triggered by emotional or physical stress, such as a panic attack; working in extremely hot weather; or strenuous coughing.
Additionally, moving from a lying down position to sitting or standing up can cause blood pressure to drop. When fainting occurs in this situation, it is usually due to dehydration, taking certain medications or illegal drugs, or heavy blood loss.
Symptoms and risk factors
A person may start to feel weak, nauseous, sweaty, lightheaded or dizzy before actually losing consciousness. Certain medical conditions can also put someone at higher risk for fainting, including:
Fainting is usually not serious; if you are in overall good health, you may not need to see a doctor. However, if you have serious health issues or take medications, speak with your doctor if you’ve fainted, as well as to discuss your risks for fainting.
Also, let your doctor know if you have experienced these additional symptoms with fainting:
- Blurry vision
- Chest pain
- Irregular heartbeat
- Shortness of breath
- Trouble talking
- Unconsciousness for more than a few seconds
- Fainting when you turn your head to the side
- Fainting more than once in a month
10 tips to avoid fainting
There are ways to prevent fainting, as well as ways to help someone who has fainted. Dr. Hans Crumpler, a family medicine doctor with SharpCare Medical Group and affiliated with Sharp Grossmont Hospital, shares these 10 tips:
- If you can do so safely, lie down and elevate your legs to just above hip level. This helps regulate blood flow and get circulation to the brain and vital organs.
- If you cannot lie down safely, try to sit down, bringing your head as close as possible to your knees. This helps redistribute blood flow to the brain. Also, there is less distance to fall, and you may potentially avoid head trauma in case you do fall.
- If you do sit or lay down, do not try to get up rapidly. Wait until your feeling of lightheadedness improves and then stand up slowly to avoid restarting symptoms.
- Try to tense up your arm muscles and make fists, which can help with blood flow in the upper body. Brace yourself to avoid hitting the ground with force if you do pass out.
- Crossing your legs or pressing them together also helps to increase blood circulation in the upper body. If standing for long periods of time, do not lock your knees because this can restrict circulation and lead to fainting.
- Avoid long periods of time without food. Eating consistently not only helps maintain your caloric needs but it also regulates blood sugar levels. Low blood sugar can cause fainting.
- Slowly drinking sips of water or electrolyte solution can help avoid passing out due to dehydration.
- Taking slow, deep breaths helps avoid fainting because it increases oxygen and blood flow in the body.
- If you see someone passing out near you, try to get them to the floor or sit them up carefully to avoid traumatic injury. Protect them from hitting objects as they come down and help them consume food or water if they respond appropriately.
- If you assist someone who has passed out, keep them still as best as you can to avoid further injury. Monitor their breathing, check for obvious injuries, and call for medical help so that the person can get a full evaluation.