Sleep Paralysis: Signs and Symptoms

Medically reviewed by Alexis Appelstein, DO

Sleep paralysis occurs when only part of your brain wakes up from sleep while the part that controls muscle movement remains turned “off.” This leaves you with a temporary feeling of paralysis; you're fully awake and alert, but unable to move your body. This temporary paralysis may be accompanied by hallucinations, anxiety, and chest pressure. An episode of sleep paralysis can be alarming, so it’s helpful to know the signs and symptoms in case it happens to you.

When it happens only occasionally, it’s known as isolated sleep paralysis (ISP). ISP is fairly common, with most people experiencing an episode at some point in their lives. If you experience episodes frequently, however, this is known as recurrent isolated sleep paralysis (RISP). RISP is considered a type of parasomnia (disruptive sleep disorder) and may be caused by other health conditions and sleep disorders.

If you’re having frequent episodes, recognizing when and how often they occur can help your healthcare provider work with you to identify the cause.

Inability to Move or Speak

The most common symptom of sleep paralysis is an inability to move or speak. In fact, this is the definition of sleep paralysis: the inability to physically control your body movements despite being otherwise awake and alert. Sleep paralysis can happen when you are falling asleep, which is known as hypnagogic/predormital, or as you wake up from sleep, which is known as hypnopompic/postdormital.

This paralysis happens because of mixed signals in the brain; as you experience REM (rapid eye movement) sleep, your brain tells your muscles not to move around too much. This prevents you from waking yourself up constantly during sleep. Then, as you awaken, your brain allows for muscle movements again. But during sleep paralysis, your brain doesn’t send that message, so while you become conscious, your body remains in a state of sleep.

Experts don’t know why this happens, especially when it is only intermittent and not recurring. RISP is more common in people with mental health conditions like bipolar disorder, people who take certain medications or use certain substances, people with irregular sleep schedules or significant stress, and people with other sleep disorders, like narcolepsy.

Hallucinations

Hallucinations are another common symptom of sleep paralysis. These can be quite vivid and involve multiple senses, including seeing things that aren’t really there, thinking you are touching or feeling something that isn’t there, and hearing sounds that aren’t actually occurring.

Common types of hallucinations include:

• Seeing flashing lights

• Seeing changing colors and patterns

• Feeling strange sensations, like tingling or vibrating

• Feeling like your body is heavier than it should be

• Feeling as if you are weightless, or floating above your body

• Smelling strange odors

• Hearing voices

• Hearing other sounds, like footsteps or music

Intense Fear or Anxiety

It can be alarming to wake up and be unable to move your body, even though episodes of sleep paralysis generally only last a few seconds to a few minutes at most. Regardless, episodes are often characterized by intense feelings of fear, anxiety, and panic.

Meanwhile, sleep paralysis-related hallucinations are frightening in their own right; many people become convinced that another presence (sometimes a malicious one) is in their room or feel like someone is sitting at the end of their bed. In fact, research shows that sleep paralysis is the cause of many reported cases of out-of-body experiences, ghostly apparitions, mystical experiences, and the appearance of “sleep demons” common in folklore.

Feelings of Pressure or Suffocation

Some people with sleep paralysis feel an increased pressure in their chest as if someone is sitting on them. There may be a biological reason for this since the muscles that control your breathing can also be affected by the same phenomena causing paralysis in the rest of your body.

However, in cases of sleep paralysis, there is also the possibility that this suffocating feeling is due to something called the incubus phenomenon, a typical hallucination among people with parasomnias and other psychiatric conditions. The incubus phenomenon is characterized by a feeling of pressure on the chest or throat combined with the visual hallucination of a creature aggressively exerting that pressure.

Symptoms in Children

Sleep paralysis can occur at any time because it can be caused by a number of factors, including medication and substance use, psychiatric conditions, sleep deprivation, and other types of sleep disorders such as narcolepsy. It tends to happen for the first time during childhood or adolescence.

The symptoms of sleep paralysis in children aren’t different than in adults, but it can be hard for parents to distinguish whether their child is experiencing normal childhood nightmares or something more troubling, like sleep paralysis, night terrors, or nightmare disorder.

If your child is routinely informing you of disturbing or scary episodes during their sleep, marked by a temporary feeling of being unable to move their body, talk with their healthcare provider. While sleep paralysis itself isn’t harmful, it could be a sign of another parasomnia or health condition.

When to Contact a Healthcare Provider

Experiencing isolated or even recurrent sleep paralysis is usually not a cause for immediate concern and typically doesn’t require emergency medical treatment. However, RISP may be caused by other conditions that can affect your overall health and quality of life in the long-term.

If you experience regular episodes of sleep paralysis—often defined as at least two episodes in a period of six months characterized by intense fear—it’s important to talk to your healthcare provider so you can identify the cause. They can help you address any co-existing conditions that could be triggering sleep paralysis.

A Quick Review

Most people will experience sleep paralysis at some point in their lives, though they may mistake it for a nightmare or other strange experience. Though it can be disturbing, including temporary body paralysis and hallucinations, sleep paralysis isn’t physically harmful.

If you have recurring episodes of sleep paralysis, it may be related to medications you’re taking, substances you’re using, a lack of sleep, or certain sleep disorders or psychiatric conditions. In that case, you may want to consider talking to your healthcare provider to identify the cause.

Frequently Asked Questions

What types of hallucinations do you have with sleep paralysis?

People can have visual, auditory, tactile, or olfactory hallucinations with sleep paralysis. In other words, you may see, smell, hear, and feel things that aren’t really there. You may also sense a presence in the room, or feel inexplicable changes to your body, like intense pressure or a feeling of weightlessness.

Should you wake someone up who is sleep paralyzed?

You don’t have to–episodes will resolve on their own, with or without intervention, and they can’t cause any physical harm. However, touching or speaking to someone who is having an episode can make it end more quickly, so you might choose to intervene if you’re able.

Do you need to go to the doctor if you have a sleep paralysis episode?

You do not need to see a healthcare provider if you have a single sleep paralysis episode. Sleep paralysis is common among the general population. But if you have recurring episodes, you may have another undiagnosed condition (narcolepsy, for example), and seeing a provider can help you treat or manage the root cause.

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