How Long Can A Person Stay Unconscious (And Why)?

How Long Can A Person Stay Unconscious (And Why)?

Exact Answer: 15 Minutes To 24 Hours

Unconsciousness is a state under which a person becomes completely unresponsive to stimuli and the person appears to be sleeping. Unconsciousness leads a person to become unresponsive towards loud sounds or shaking. Sometimes the person even stops breathing or the pulse may also become faint.

There are multiple symptoms that indicate the occurrence such as sudden inability to respond, slurred speech, rapid heart rate, confusion, dizziness or lightheadedness, etc. In any case, if a person is not able to breathe due to unconsciousness, it is advised to give them CPR immediately.

How Long Can A Person Stay Unconscious

How Long Can A Person Stay Unconscious?

In most of the cases, a person stays unconscious for about 15-30 minutes. But sometimes, being unconscious for a longer period of time leads to concussion and in some cases might lead to the person going in coma or permanent brain damage. If a person shows any symptoms of unconsciousness, then it is very important to give immediate medical attention.

Unconsciousness is caused by any major illness or injury. Drug or Alcohol addicts are more likely to get unconscious than a normal person. Low levels of Blood Sugar, Low Blood Pressure or Dehydration result in Brief Unconsciousness. Sometimes unconsciousness also restricts the body movement for a few hours and might also hamper the heartbeat rate. It is advised not to splash water on an unconscious person in a bid to revive them.

Brain injuries that lead to the loss of a lot of blood are one of the primary reasons for long term unconsciousness. A stroke to the brain also results in a person becoming unconscious for a few hours. It is advised to place the unconscious person in supine position with feet elevated. Under a large number of instances of unconsciousness, hypertension is evident.

Duration Of UnconsciousnessCauses Of UnconsciousnessResult
15 minutes to 3 hoursDehydration or Minor Injuries on the HeadDizziness or Lightheadedness
6 hours to 18 hoursStroke in Brain or Low Blood PressureTemporary Brain Damage or Short-term Memory Loss
More than 24 hoursRoad Accidents or Heavy Blow to HeadComa, Death or Permanent Brain Damage

Why Does A Person Stay Unconscious For That Long?

Unconsciousness last that longer because the working of brain is hindered. Sensory Neurons which are responsible for bringing information about the body are not able to communicate properly with the brain and this results in the person remaining unresponsive towards daily-to-daily stimuli.

In most of the cases the blood flow to the brain is ceased due to which there is a loss of oxygen in the brain as a result the brain is not able to metabolize glucose and convert it into energy which results in a person becoming unconsciousness. Low Blood Pressure or High Blood Pressure is also responsible for causing unconsciousness for considerable amount of time. Heart Patients get unconscious because of lack of blood flow.

In some cases, the airways get blocked which doesn’t allow the person to breathe properly and result in unconsciousness. If the person is not able to regain oxygen by breathing in about 10-15 seconds, unconsciousness lasts longer. In a very less percentage of cases, an unconscious person might remain awake for a few hours without responding to any stimuli right up until they die.


On an average, it can be concluded that a person remain unconscious from 15 minutes to a few hours. Generally, the person becomes conscious by its own or by home remedies but if the person doesn’t respond even after a few hours, it is highly recommended to call a medical practitioner to look into the situation.

There are multiple causes of Unconsciousness namely Imbalance of Heat, Shock, Head Injury, Epilepsy, Diabetes, Stroke, Poisoning, Heart Diseases, Alcohol or Drug Use and many more. It is advised to lie down an unconscious person on his/her back and face looking upwards in an open air environment and lift the person’s chin upwards for oxygen to pass easily.


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Hi! I'm Nidhi.

Here at the EHL, it's all about delicious, easy recipes for casual entertaining. So come and join me at the beach, relax and enjoy the food.


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