Passing out (syncope) feels like a sudden, brief loss of consciousness, often preceded by warning signs like dizziness, tunnel vision (seeing spots/blurry), lightheadedness, nausea, sweating, paleness, and a weak or unsteady feeling, as blood flow to the brain temporarily drops, leading to unresponsiveness for a few seconds before a quick recovery.
Fainting is when you suddenly lose consciousness and become unresponsive for a few seconds. Before you faint, it is common to get warning signs such as weakness, dizziness, nausea, vision changes or anxiety.
If you're about to faint, you'll feel dizzy, lightheaded, or nauseous. Your field of vision may "white out" or "black out." Your skin may be cold and clammy. You lose muscle control at the same time, and may fall down.
Symptoms of fainting
Fainting usually happens suddenly. Symptoms can include: dizziness. cold skin and sweating.
Pre-syncope is the feeling that you are about to faint. Someone with pre-syncope may be lightheaded (dizzy) or nauseated, have a visual "gray out" or trouble hearing, have palpitations, or feel weak or suddenly sweaty.
This can happen for various reasons, including nerve-related conditions. Vasovagal syncope (the most common cause of fainting) happens when the vagus nerve, which helps regulate heart rate and blood pressure, reacts too strongly to triggers like stress, dehydration, or the sight of blood.
Fainting and seizures can be confused because they sometimes share similar symptoms: Convulsive syncope: It is estimated that between 6% and 25% of of people with the most common kind of syncope (vasovagal syncope) have convulsions. To the untrained eye, this may look like an epileptic seizure.
Some people use the terms blackout and fainting interchangeably, but they are different things. A blackout is a loss of memory. Fainting, also called passing out, is a loss of consciousness. Both of these can have several different causes.
The vasovagal reflex (vasovagal syncope), which causes your heart rate to slow and the blood vessels to widen. This reflex can be triggered by many things, including stress, pain, fear, coughing, holding your breath and urinating. The vasovagal reflex accounts for most fainting episodes.
What Are the Warning Signs of Fainting?
Presyncope is staying conscious while feeling like you're about to faint. Some providers call this common condition near syncope. Syncope is a medical term for fainting. Presyncope (pree-sing-kuh-pee) can last a few seconds to a few minutes.
But fainting may be serious if you felt chest pain, confusion or shortness of breath (dyspnea) when you fainted. This is a case where you should see a provider.
Dizziness
Dizziness is defined as feeling like the room is spinning or you are going to pass out. This can be due to a slow or fast heart rhythm, and can indicate that your heart's electrical system is not firing properly. “This could be a sign of an arrhythmia, or of a heart valve condition,” Dr.
During a vasovagal syncope episode, you may experience: Brief disorientation or confusion. Eyes staying open but rolling up and back into your head. Falling when you lose consciousness.
While most people wake up quickly and feel fine afterward, that doesn't always mean the fainting episode was nothing to worry about. Fainting, also called syncope (pronounced SING-kuh-pee), can sometimes be a sign of a health issue that needs medical attention.
If there are no injuries and the person is breathing, raise the person's legs above heart level if possible. Prop up the person's legs about 12 inches (30 centimeters). Loosen belts, collars or other tight clothing. To reduce the chance of fainting again, don't get the person up too fast.
The cerebral cortex is thought to be the seat of conscious processing in the brain. Rather than being inactivated, specific cells in the cortex show higher spontaneous activity during general anesthesia than when awake, and this activity is synchronized across those cortical cells.
Most fainting will pass quickly and won't be serious. Usually, a fainting episode will only last a few seconds, although it will make the person feel unwell and recovery may take several minutes. If a person doesn't recover quickly, always seek urgent medical attention.
Prior theories suggest that fainting may reduce blood loss in injury by lowering blood pressure, prevent cardiac damage through vagal braking, [2] or improve cerebral perfusion through sudden horizontal posture [3].
However, it may be indicative of underlying health conditions, such as low blood pressure, abnormal heart rhythm, hypoglycemia or stress, so the person should seek follow-up medical attention. If someone faints or appears to be fainting, call 911 or your local emergency number.
Most unexplained blackouts are caused by syncope
Many people, including doctors, assume that blackouts are due to epileptic seizures, but much more commonly they are due to syncope (pronounced sin-co-pee) – a type of blackout which is caused by a problem in the regulation of blood pressure or sometimes with the heart.
Unconscious patients experience diminished alertness, decreased self-awareness, and impaired responsiveness to external stimuli. Unconsciousness can result from damage to the ascending reticular activating system, cerebral hemispheres, or various toxic, metabolic, or infectious causes.
During fainting, “seizure-like” activity may occur. This shaking or stiffening is thought to be distinct from a true seizure and is due to the brain being briefly deprived of oxygen and blood flow.
A loss of consciousness occurs when not enough blood reaches the brain and corresponds to a loss of awareness of oneself and one's surroundings.