When someone is unconscious, they cannot be woken by shouting, tapping their shoulder, or any other stimulation. The most important thing to do immediately is check whether they are breathing normally. That single observation determines everything that follows: a breathing person needs to be placed on their side to protect their airway, while a person who is not breathing needs CPR and an emergency call right away.
What to Do in the First 60 Seconds
Start by trying to get a response. Call the person’s name loudly, tap their shoulders firmly, and shout again. If they don’t react at all, you’re dealing with true unconsciousness rather than sleep or confusion. Next, look at their chest for 10 seconds to check for normal breathing. Gasping or gurgling does not count as breathing.
If the person is not breathing or is only gasping, call 911 immediately and begin CPR. Push hard and fast on the center of the chest, compressing at least 5 centimeters (about 2 inches) deep but no more than 6 centimeters. Give 30 compressions, then 2 breaths, and repeat. Each breath should produce visible chest rise. If an automated external defibrillator (AED) is nearby, have someone retrieve it and follow the voice prompts while you continue compressions.
If the person is breathing normally, call 911 and place them in the recovery position while you wait for help. If the person does not regain consciousness within one minute, that alone warrants an emergency call. A faint or absent pulse, blue-tinged lips, or seizure activity all require immediate emergency attention.
How to Place Someone in the Recovery Position
The recovery position keeps the airway open and prevents choking if the person vomits, which is common during unconsciousness. Blood, saliva, or stomach contents can block the airway in seconds when someone is flat on their back, turning a survivable situation into a fatal one.
Kneel beside the person. Take the arm closest to you and extend it straight out from the body. Then take their far arm and place the back of that hand against the cheek nearest to you. With your other hand, grab the person’s far knee and bend it. Gently pull that bent knee toward you so the person rolls onto their side, using your hand to protect their head as they turn. Tilt the head slightly upward to keep the airway open, making sure the hand stays tucked under the cheek for support. Cover them with a blanket or coat to maintain warmth, and stay with them until help arrives.
One critical exception: do not roll someone into the recovery position if you suspect a head, neck, or back injury. Leave them in the position you found them unless you absolutely must move them to perform CPR or control severe bleeding.
Common Causes of Unconsciousness
The most common reason a person suddenly loses consciousness is fainting, medically called syncope. This happens when blood pressure drops sharply and the brain briefly loses adequate blood flow. Reflex syncope (sometimes called vasovagal syncope) accounts for the majority of cases. It can be triggered by standing too long, overheating, dehydration, sudden pain, or the sight of blood. Standing up too quickly causes a related form called orthostatic syncope, which is especially common in older adults and people on blood pressure medications.
Cardiac causes are less common but more dangerous. Abnormal heart rhythms or structural heart problems can cut off blood flow to the brain without warning. Seizures are another major category. During a generalized seizure, a person loses consciousness and may convulse, stiffen, or go limp. The period of unresponsiveness after a seizure (called the postictal state) can last minutes to hours.
Other causes include severe low blood sugar (hypoglycemia), head injuries, strokes, drug or alcohol overdoses, heatstroke, and severe allergic reactions. In some cases, unconsciousness has a psychological origin where the body mimics a faint or seizure without a physical trigger.
Warning Signs Before Losing Consciousness
People who are about to faint often experience a recognizable set of warning signs in the seconds or minutes beforehand. These include dizziness, lightheadedness, blurred or tunneling vision, nausea, and cold or clammy skin. Some people describe a feeling of the world “closing in” or notice their hearing becoming muffled. If you or someone near you reports these symptoms, sitting or lying down immediately can prevent a fall and the injuries that come with it.
Special Situation: Diabetic Emergencies
If the unconscious person is known to have diabetes, severely low blood sugar is a likely cause. This is considered a medical emergency. The most important rule: never try to put food or liquid into an unconscious person’s mouth. They cannot swallow safely, and anything you give them can enter the lungs instead.
Many people with insulin-treated diabetes carry a glucagon kit, which is an injectable medication that rapidly raises blood sugar. If you can find the kit and know how to use it, administer it. If you can’t locate one or aren’t sure how it works, call 911 immediately. Paramedics can deliver glucose intravenously, which works within minutes.
How Medical Teams Assess Unconsciousness
When paramedics and emergency doctors evaluate an unconscious person, they use a standardized scoring system called the Glasgow Coma Scale. It measures three things: whether the eyes open, whether the person makes any sounds, and whether the body moves in response to stimulation. Scores range from 3 (completely unresponsive) to 15 (fully alert). This score gives medical teams a quick, shared language for how deep the unconsciousness is and whether it’s getting better or worse over time.
Doctors also check the pupils. Normally, both pupils constrict equally when a light is shone into the eyes. When one or both pupils are fixed and don’t react to light, it can signal serious brain involvement, such as pressure building inside the skull. Pupil responses are one of the most important tools in predicting outcomes for patients who remain unconscious in intensive care.
If a Spine Injury Is Suspected
When unconsciousness follows a fall, car accident, sports collision, or any other trauma, there is always a risk that the spine has been injured. Moving someone with an unstable neck fracture can cause permanent paralysis. The safest approach is to keep the person completely still in the position you found them. If multiple bystanders are present, one person can gently stabilize the head and neck by holding them in a neutral position with both hands, preventing any rotation or tilting.
In the hospital, medical teams use hard collars and imaging scans to check for fractures before clearing the spine. If the patient is not expected to regain consciousness within 48 to 72 hours, doctors may rely on CT scans alone to determine whether it’s safe to remove spinal precautions. For bystanders, the takeaway is simple: don’t move a trauma victim unless their life depends on it, such as when they’re not breathing and need CPR or when they’re in immediate danger from fire or traffic.