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Sleep occurs in various stages that continue in cycles throughout the night. One of the stages of sleep is called rapid eye movement (REM). The REM stage is important for health and brain function.
Rapid eye movement behaviour disorder (RBD) is a rare parasomnia or unusual behaviour that happens during REM sleep.
Usually, our brain sends messages to our body that put our muscles into a type of temporary paralysis while we are in REM sleep; this is known as muscle atonia. It enables our brains to remain active whilst our bodies remain still. During an RBD episode, this mechanism fails and people physically react to, or act out, their dreams.
It is important to know the signs of RBD because it can signify an underlying health condition, including a serious neurological problem.
What is RBD?
Rapid eye movement behaviour disorder (RBD) is a type of sleep disorder that happens during the REM stage of sleep.
Other REM sleep disorders include:
- Recurrent isolated sleep paralysis
- Nightmare disorder
The majority of dreams take place during REM sleep and dreams during this stage of sleep are usually more vivid and intense than dreams during non-REM sleep.
REM sleep disorder, or RBD, usually take place when something interrupts the information that is sent from the brain down the spine and to the muscles. This normally happens because there is a problem in the part of the brain that is responsible for this type of communication, meaning these messages are not sent correctly.
During normal REM sleep, the brain communicates with the body to tell the muscles to remain still. When this communication fails, it can sometimes trigger episodes of RBD, meaning that rather than lying still in bed and dreaming safely, people will move, thrash about and become vocal.
When people have rapid eye movement behaviour disorder they begin literally ‘acting out’ their dreams.
Symptoms and diagnosis
Rapid eye movement behaviour disorder is characterised by unusual, disruptive and sometimes dangerous behaviours that happen during sleep. People are usually totally unaware of what they are doing.
During RBD, people will start acting out what is happening in their dreams. This might look like:
- Speaking, shouting or calling out
- Trying to defend themselves
- Trying to strike or hit something
- Kicking the legs
- Flailing the arms
- Muscle twitches
- Jumping or falling out of bed

Anyone concerned that they may have a sleep disorder should make an appointment to see their GP. Usually, doctors will want to know information about any symptoms and their patient’s general health.
To help with this, it may be useful for a patient to:
- Keep a sleep diary, recording any relevant information including injuries sustained during disturbed sleep
- Find out details about any family history of parasomnia or neurological conditions
- Have a list of any medication (prescribed or over the counter) in case it is contributing to RBD symptoms
Patients should expect to undergo a physical examination and possibly a neurological examination or further tests.
If a sleep disorder is suspected, a doctor may decide to refer a patient to a sleep clinic for observation. At specialist inpatient facilities, patients are usually monitored for one or two nights as part of a ‘sleep study’, also known as polysomnography.
During polysomnography, patients are fitted with a series of wires which are used to monitor their body during sleep. Observations will be made about their behaviour during REM sleep, including:
- Heart rate
- Breathing
- Brain wave activity
- Eye movements
- Muscle movements and muscle tension
- Oxygen levels
Specialists will use the diagnostics collected to look for signs of RBD (such as the unusual behaviours occurring during REM sleep rather than non-REM sleep or a lack of muscle atonia) and to rule out symptoms being caused by another mental health or health condition.
Causes and risk factors
In the vast majority of cases, it is not possible to prevent RBD. It can be a warning sign of other conditions, be a result of taking medication or other substances, or sometimes it can occur for no apparent reason.
There are a number of factors that can contribute to RBD developing, for example:
- Stress – stress impacts sleep quality and can make symptoms of REM behaviour disorder worse.
- Underlying health conditions – RBD is linked with neurological conditions.
- Certain medications – antidepressants, beta blockers and some medications taken for Alzheimer’s can cause REM sleep disorder or make it worse. Your GP can discuss this with you further. You should not stop taking medication unless instructed to do so by a doctor.
Other risk factors for developing the condition may include:
- Gender – males may be more likely to develop REM disorders
- Age – those over the age of 50 are thought to be more at risk
- Psychology – Post Traumatic Stress Disorder (PTSD) may make a person more likely to develop RBD
- Other sleep disorders – RBD has a correlation with other parasomnias, such as narcolepsy
- Withdrawing from drugs or alcohol – may increase the risk of RBD

RBD and neurological disorders
RBD is linked with neurological disorders. A neurological disorder is a condition that affects the brain, spinal cord or peripheral nerves, resulting in problems with cognitive function, movement, sensation, or other aspects of nervous system functioning.
REM sleep disorders are associated with some of the following neurological disorders:
Parkinson’s disease
Parkinson’s disease is a progressive nervous system disorder that affects movement and motor control. It occurs when nerve cells in the brain that produce a chemical called dopamine become damaged or die. Dopamine is essential for transmitting signals between the brain and muscles. It enables movements to be smooth and coordinated.
As dopamine levels decrease, patients experience symptoms such as tremors, stiffness, slowed movements, and difficulty with balance and coordination. The exact cause of Parkinson’s disease is unknown, but it is believed to involve a combination of genetic and environmental factors. There is currently no cure, but medications and other treatments can help manage symptoms and improve quality of life.
Lewy body dementia
Lewy body dementia (LBD) is a progressive brain disorder characterised by the presence of abnormal protein deposits called Lewy bodies in the brain. These deposits affect the functioning of nerve cells, leading to problems with cognitive function, movement and behaviour. LBD can cause symptoms similar to both Alzheimer’s disease and Parkinson’s disease, making it difficult to diagnose.
Common symptoms include memory loss, difficulty with problem-solving, fluctuating cognitive abilities, visual hallucinations, sleep disturbances, and changes in movement, such as stiffness and tremors. There is no cure for LBD, but medications and other treatments can help manage symptoms and improve quality of life.
Multiple system atrophy
Multiple system atrophy (MSA) is a rare neurodegenerative disorder that affects the brain and spinal cord. It causes progressive damage to the nervous system, leading to problems with movement, balance, coordination and autonomic functions.
MSA can also affect speech, swallowing and cognitive abilities. The disease is characterised by a loss of brain cells and a build-up of abnormal protein clumps called glial cytoplasmic inclusions. Currently, there is no cure for MSA, and treatment focuses on managing symptoms and improving quality of life.
Living with RBD
It is common for people who experience RBD to sustain injuries as a result. Sometimes they may even accidentally injure their partner as well.
Injuries sustained may include:
- Bruises
- Scratches/grazes
- Sprains
- Head injuries
- Broken bones
As a person is unaware of what they are doing while they are asleep and the possibility of them causing injury to themselves or others if they have RBD is likely, it is important to create a safe and secure sleep environment. This can be done by putting specific safeguards in place.
Various physical safeguards can be used to prevent injuries from RBD, such as:
- Putting soft padding or barriers around the bed
- Moving furniture or any sharp objects away from the bed
- Placing a pillow or bolster between partners during sleep
- Swapping metal headboards for softer, padded ones or buying a low bed if falling out of bed is a recurring issue
- In severe cases, people may be advised to sleep separately from their partner in another room
Sleep is a vital part of living a healthy life. It is important that people get an adequate amount of good quality sleep. Taking steps to make sure this happens is sometimes called sleep hygiene. A responsible approach to sleep can help people to function, feel rested and be healthy and can also help to manage sleep disorders.
A good sleep hygiene routine may look like:
- Regular bedtimes
- Regular wake-up times
- A quiet, comfortable sleeping environment
- Avoiding excessive caffeine (especially in the latter part of the day)
- Avoiding overstimulation just before sleep
- No blue light just before bed (blue light is emitted from electronic devices such as mobile phone screens)
- Practising relaxation, meditation or mindfulness before bed
- Avoiding sedatives (including alcohol) to promote a natural sleep
Unlike other parasomnias, such as night terrors, if a person is experiencing an episode of RBD, it is usually quite easy to wake them up. It is common for people to be able to remember what they were dreaming about even though they will have no idea that they were acting out their dreams.
RBD episodes may occur once a night or several times and they usually get worse and more frequent over time.
Treatment and management
If you have rapid eye movement behaviour disorder or suspect that you may have, it is important to consult a qualified healthcare professional for help and advice.
REM sleep behaviour disorder may be treated with medication, lifestyle changes or a combination of both.
Some of the common medications used to treat the condition are:
- Clonazepam – this is a sedative medication. It helps to keep people calm and still during the night. Clonazepam can have undesirable side effects, including tiredness during the day, balance problems and slower breathing during the night.
- Melatonin – this is a hormone that the body makes naturally. It plays a key role in regulating the sleep cycle. Taking synthetic melatonin helps with the symptoms of RBD and it normally has less significant side effects than clonazepam.

Raising awareness
Sometimes, RBD is the first sign of a more serious health problem. Many people who suffer from rapid eye movement behaviour disorder will go on to develop a serious neurological disorder such as Parkinson’s disease or Lewy body dementia. This can happen years or even decades later, and the RBD occurrences are often the first sign that something is wrong.
In addition to understanding the link between RBD and neurological problems, it is important to raise awareness about parasomnia because:
- Hurting oneself or others during the night can be painful and distressing.
- The feeling of not being in control of our behaviour can also make people feel anxious so understanding what is happening and why can help people gain a sense of control back.
- Whilst research is ongoing into all aspects of parasomnia, including RBD, it is important that people understand how to reach out for help and what safeguards they can put in place. This can minimise the chance of anyone being hurt.
- A safe and restful night of sleep is vital for maintaining good mental and physical health. Simple changes and safety measures can help people who suffer from RBD (and their partners) to have a safer and better quality night’s sleep.
- Education is key in promoting empathy and understanding and raising awareness about underreported or misunderstood health conditions.
Although experiencing RBD is not always a precursor to something more serious, because of the correlation between RBD and neurological problems in later life, it is very important to take note of unusual behaviour that is happening during sleep.
Your doctor may be able to offer insight into what is happening and, if necessary, make a referral to a specialist or sleep clinic. Once you have a diagnosis, it is easier to start taking the right steps to minimise the impact that having a sleep disorder has, on both you and your loved ones.