The medical term for fainting is syncope, a short loss of consciousness and muscle tone caused by a temporary drop in blood flow to the brain, followed by full recovery on its own. Passing out, blacking out and keeling over all describe the same event in everyday speech.
Syncope is said SIN-kuh-pee, and the word comes from Greek roots meaning a cutting short. The feeling of almost fainting, with lightheadedness, tunnel vision or sweating but no full blackout, is called presyncope or near syncope. This page sorts out the main types, the chart shorthand that travels with them, and how syncope differs from a seizure.
At a glance
Medical term
SyncopeNear fainting
Presyncope, near syncopeAdjective
Syncopal, as in syncopal episodeCommon type
Vasovagal syncope, the ordinary faintRelated shorthand
LOC, loss of consciousnessDo not confuse with
Seizure, vertigo, or simple dizziness
Defining syncope, the medical term for fainting
Syncope has three parts in its definition: it is sudden, it is brief, and the person recovers fully without treatment such as shocks or medicine. The cause is a short fall in blood flow to the brain, often from a drop in blood pressure, a slow or irregular heartbeat, or blood pooling in the legs.
Losing consciousness for other reasons, such as a head injury, low blood sugar or a seizure, is not called syncope even if it looks similar from across the room. That is why a clinician asks so many questions about what happened right before, during and after an episode.
Types of syncope you may see in notes
| Type | What is going on | Typical trigger |
|---|---|---|
| Vasovagal | A reflex slows the heart and widens blood vessels | Pain, the sight of blood, standing a long time, heat, stress |
| Situational | A reflex tied to a specific act | Coughing, straining, urinating, swallowing |
| Orthostatic | Blood pressure drops on standing | Dehydration, some blood pressure medicines, nerve conditions |
| Cardiac | The heart cannot pump enough for a moment | Rhythm problems or structural heart disease |
Vasovagal syncope is by far the most common, especially in younger people. Cardiac syncope is less common but gets the most attention, because it can point to a heart problem that needs care. Some people with POTS have presyncope or fainting when they stand.
Reading a syncope note line by line
Emergency department note: "CC: syncope at church, brief LOC, rapid return to baseline. Prodrome of warmth and nausea. No incontinence or tongue biting." The chief complaint is a faint. The person lost consciousness briefly and came back to normal quickly. Prodrome means warning signs before it happened. The last sentence notes the absence of features that lean toward a seizure.
Other common terms include orthostatic vital signs, which compare blood pressure and heart rate lying down and standing, and an EKG, which looks for rhythm problems. A note may also mention telemetry, meaning continuous heart monitoring.
Fainting, seizure or dizziness?
A faint usually comes with warning signs such as lightheadedness, feeling hot, sweating, nausea or graying vision, and the person wakes within a minute or so and is clear headed soon after. A few jerks of the arms can happen during a faint, which confuses onlookers.
A seizure is an electrical event in the brain. It may come without warning, last longer, and be followed by confusion or sleepiness for a while. Vertigo is a spinning sensation, and dizziness is a broad word people use for many feelings, so clinicians ask patients to describe exactly what they felt. Anyone who faints and does not wake quickly, has chest pain, a pounding heartbeat, or faints during exercise needs emergency care.
For students and scribes
Write syncope or syncopal episode, not passed out, in the clinical part of the note. If the patient only felt faint, use presyncope. Record what witnesses saw, how long it lasted, and whether the person was injured, since a fall can add a ground level fall or head injury to the picture. Find related terms in the medical terminology guide.
Learning the word is the easy part; finding the cause of a faint takes a clinical evaluation. After any fainting spell, a doctor or nurse can advise on what checks are needed.
Frequently asked questions
What is the medical term for passing out?
Syncope is the medical term for passing out from a brief drop in blood flow to the brain. Notes may also call it a syncopal episode.
What is the medical term for almost fainting?
Presyncope, also called near syncope. It describes lightheadedness, tunnel vision or weakness without fully losing consciousness.
How do you pronounce syncope?
Say SIN-kuh-pee, three syllables with the stress on the first. The adjective syncopal is said SIN-kuh-pul.
What is vasovagal syncope?
It is the most common kind of fainting, caused by a reflex that slows the heart and lowers blood pressure. Triggers include pain, standing for a long time, heat and the sight of blood.
Is fainting the same as LOC?
Fainting causes loss of consciousness, but LOC can have many other causes, such as head injury or seizure. Syncope is the specific term for the short, self correcting kind.