From nightmares to bizarre nocturnal visions: What your dreams can reveal about your health

By Kate Wighton

PUBLISHED: 19:30 EST, 14 October 2013 | UPDATED: 04:53 EST, 15 October 2013

You might find discussing the meaning of dreams fascinating, but dream analysis has long been regarded by medics as no more meaningful than astrology.

However, scientists now think dreams may, in fact, provide vital clues about our health - and even give early warnings of conditions years before physical symptoms appear.

Exactly why we dream still mystifies scientists - and provokes fierce debate. What is known is that most of us have around four to six dreams a night, but we remember only around two or three a week.

Informative: Scientists now think dreams may provide vital clues about our health

Informative: Scientists now think dreams may provide vital clues about our health

The reason for this is that we recall a dream only if we wake up in the middle of it; if we continue sleeping when the dream ends, then we have forgotten it for ever.

Women seem to remember their dreams much more frequently than men, possibly because they tend to be lighter sleepers.

We don't dream all night. The brain starts to create them only when we switch into a particular type of 'dreaming sleep' called rapid-eye movement (REM) sleep.

 

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And because this is a very light form of sleep, we wake easily during dreams.

We have this type of sleep around four times a night, with the first bout starting around 90 minutes after we drop off.

So what is the latest thinking about dreams and their meanings? Whether you're dreaming more than usual, or having nightmares or strangely vivid dreams, we look at what this might reveal about your health . . .

NIGHTMARES

POSSIBLE CAUSES: Beta-blockers, heart conditions, migraine or sleep deprivation.

The blood pressure pills beta-blockers are notorious for 'quite nasty dreams', says Professor Jim Horne, a sleep expert from Loughborough University.

These widely used medications help widen blood vessels, but experts believe they may also indirectly alter the balance of certain brain chemicals, which then triggers nightmares.

Bad dreams can also be linked to a dicky heart, according to a study of more than 6,000 people published in the Netherlands Journal of Medicine. This found that suffering from an irregular heartbeat increases the risk of nightmares threefold, while suffering from chest pain increases it sevenfold.

This could be because people with heart problems are more likely to suffer from breathing problems, which may lower  oxygen levels in the brain.

Night terrors: Nightmares can be linked to blood pressure pills ('beta-blockers') and a dicky heart

Night terrors: Nightmares can be linked to blood pressure pills ('beta-blockers') and a dicky heart

Nightmares can also be a warning of an impending migraine. These excruciating headaches can strike at night, and one study of 37 patients found they are often preceded by bad dreams that usually involve themes of anger and aggression. One theory is that the headaches can cause changes in the brain.

But it could just be a lack of shut-eye triggering your nightmares. Too little can trigger the condition sleep paralysis, which affects around one in 20 of us at some stage in life, says Dr Nicholas Oscroft, a sleep expert from Papworth Hospital in Cambridge.

This condition leaves a person unable to move for a few moments after they wake due to a malfunction in the system that controls our muscles. (Muscles are paralysed when we dream so that we don't act them out and  hurt ourselves.)

As if this isn't bad enough, a person with sleep paralysis will also frequently experience the feeling that there is someone in the room with them, or that someone is pressing on their chest.

Luckily, this usually only lasts for a minute or two, but it can leave a person terrified.

MORE DREAMS THAN USUAL

POSSIBLE CAUSES: Getting too hot or cold in the night, hormones, chronic pain or coming off antidepressants.

Overheating or feeling chilly at night can lead to us having more dreams, says Professor Horne.
'The more disturbed your sleep - perhaps by being too hot or too cold - the more likely you are to wake during dreaming sleep, which means you'll remember your dreams,' he adds.

Experts recommend having your bedroom at around 18c. For the same reason, the fluctuation in a woman's hormones can also cause her to have more dreams.

'Some women say that they have more dreams around the time of their period,' says Professor Horne. 'This could be because some women get very uncomfortable, with bloating or cramps, causing them to wake up more.' Insomnia and pain can also cause people to wake up repeatedly during the night, meaning they remember more of their dreams.

Dr Oscroft adds that having a few nights of poor sleep will also lead to a night full of vivid dreams.

Having too little sleep, say four to six hours, deprives our brain of the usual amount of dreaming sleep, which means that we build up a 'debt'. Payback comes when we have the first night of proper rest - and we experience much longer periods of dreaming sleep.

This is known as rapid-eye movement rebound.

It can also occur when a patient stops taking antidepressants. This is because many of the commonly used antidepressants can drastically reduce the amount of REM or dreaming sleep, says  Dr Oscroft.

DREAMS OF BEING ATTACKED

POSSIBLE CAUSES: Alzheimer's  or Parkinson's.

Acting out stressful dreams, such as when you're being attacked or chased, can be an early sign of a brain or nerve disease like Alzheimer's or Parkinson's, says Dr Oscroft.

People who regularly flail and thrash about during dreams are thought to suffer from a condition called REM sleep behaviour disorder. It's believed to be caused by damage in the part of the brain that controls our dreaming 'safety switch', which normally prevents us from acting out our dreams.

This condition causes very violent, disturbing dreams - such as being chased or attacked - and causes the dreamer to lash or kick out, sometimes injuring themselves or their partner.

It is a strong predictor of diseases such as Alzheimer's, and can sometimes appear up to ten years before any other symptoms like memory loss.

'It can be the first symptom we see,' says Dr Oscroft. 'I warn people diagnosed with this to look out for other warning signs of neurological disease, such as tremors or memory loss, as this will enable them to get early treatment.'

DREAMS THAT WAKE YOU EARLY

POSSIBLE CAUSES: Eating a  fatty meal, being overweight, stress or depression.

Large, fatty meals tend to sit in the stomach for longer, says Professor Horne. This puts pressure on the valve between the stomach and the gullet, and can cause food and stomach acid to splash back up, triggering heartburn.

Abrupt awakening: Dreams that wake you early are often a result of having eaten a fatty meal the night before, or obesity, stress or depression

Abrupt awakening: Dreams that wake you early are often a result of having eaten a fatty meal the night before, or obesity, stress or depression

This usually happens in the first hours after falling asleep, and so is likely to wake someone early in the night and, therefore, in the dreaming stage.

They're also likely to wake up spluttering as the acid splashes back up the throat.

Acid reflux is also more common in those who are overweight, as the extra fat can press on the valve and weaken it, making waking early on more common.

People with depression or severe stress also seem to enter dreaming sleep much earlier - and so have dreams earlier in the night - adds Professor Horne, although doctors are unsure why.

MEMORABLE OR BIZARRE DREAMS

POSSIBLE CAUSES: Alcohol, infection, anti-malarial pills or the menopause.

A late-night tipple can trigger especially memorable dreams just before you wake up, says Professor Horne.

'If people have a skinful, they can find themselves having powerful, vivid dreams towards the end of the night. This is because the effects of alcohol seem to wear off towards morning, which may affect brain chemicals in some way and cause strange dreams.'

Being under the weather can also cause a surreal half-sleep, half-awake state, triggering bizarre dreams, says Dr Patrick McNamara, a neurologist from Boston University Medical School. 

When our body comes under attack from a bug, our immune system needs to use all its power to fight it. Sleep can help, as a particular type of the deep, non-dreaming kind - called slow-wave sleep - seems to boost our defences.

'Any infection increases the amount of slow-wave sleep we have,' says Dr McNamara.

However, this delays the starting point of when we enter dreaming sleep, so 'dreaming sleep starts late, and can erupt into consciousness', he adds. 'This leads to vivid dreams and strange hallucinations.'

Medications can also trigger vivid dreams, he explains.

'Many patients have told me antibiotics trigger vivid dreams, but I know of no studies into this. However, the anti-malarial drug mefloquine is well known to trigger “epic dreams” - long stories with lots of colour and unusual characters or bizarre monsters.'

One theory is these drugs disrupt levels of the brain chemical acetylcholine, which play a crucial role in controlling our dreams.

Many women find dreams get particularly vivid around the menopause, adds Professor Horne. This might be due to fluctuating hormone levels.

SEXUAL DREAMS

POSSIBLE CAUSES: Increased creativity.

Sexual dreams: These correlate to increased levels of creativity and are particularly common among the over-60s

Sexual dreams: These correlate to increased levels of creativity and are particularly common among the over-60s

Dreams of a sexual nature are common throughout all ages but increase as we get older, and are particular common among the over-60s, says psychologist Ian Wallace.

'Many of my clients in their 60s and 70s report having these. Surprisingly, they don't actually represent anything about their sex life, but are connected to increased levels of creativity.'

People often take up new hobbies in retirement, which could explain the increased number of sexual dreams they experience.

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Since June 2011 I have had regular nightmares involving being chased, someone trying to kill me, and often wake gasping for breath. Over the last three months it has been worse. The stange thing is that during this time I have had a total of five heart attacks and in July was prescribed anti-depressants. Do you think Kate Wighton used my medical notes for this article

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Since June 2011 I have had regular nightmares involving being chased, someone trying to kill me, and often wake gasping for breath. Over the last three months it has been worse. The stange thing is that during this time I have had a total of five heart attacks and in July was prescribed anti-depressants. Do you think Kate Wighton used my medical notes for this article

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I eat regularly a little lump of cheese just before I go to bed to ensure I have some jolly good dreams ! I love waking up in the morning and feel I've been travelling far afield !

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Crap, I'm a creative,overweight, alcoholic with Parkinson's... thanks WebMD,oh... wait.

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I had a dream once where I couldnt kill zombies as it went against there human rights!! That is just one of many mad dreams I have had in this lifetime... I must mean I am really poorly then!!

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I wonder if we dream after we are dead? zzz!

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LOOKS LIKE IM FEELIN CREATIVE!

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Dream analysis via the internet or dream books are a pure waste of time and money. Dreams are idiosyncratic, there is no one size fits all. There is a process that allows for first of all to decipher the dream and it's theme utilizing your unconscious mind then pulling out its meaning consciously. Nightmares and vivid dreams are about something in your life that needs attention NOW! Most other kinds of dreams are about what you need to do next or an unconscious realization that you've changed in some way that even your conscious mind hasn't been fully aware of. The best book describing this process and from which you can learn in detail about how you can do it yourself is "Decipher your Dreams, Decipher Your Life" by Tina Galgano.

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Which doctor said this? Where are the studies to back this up? Just a load a nonsense, I have extremely vivid dreams - in fact have experienced each "type" of these for the past 15 years and don't have any conditions. The worst nightmares usually came when I was coming off medications, and is easily explained as rebound REM sleep.

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Sleep paralysis is scary stuff!!! It occurs when demons attempt to inhabit your body and take it as their own. Be careful, people!

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