Sleep apnoea. Insomnia. Narcolepsy. Most of us are familiar with a slew of sleep disorders. But we bet you've never heard of the one that makes you hear loud crashes just before you nod off to sleep...
For most of us, sleep is a blissful blanket of warmth, tenderly transporting us away to a wondrous dream-world of soothing slumber. For others, it's a Stephen King Novel. At least that's what these five very bizarre but very real sleep disorders would have us think.
Warning: Not for bed time reading.
1. Exploding head syndrome
One of the more peculiar sleep disorders out there is characterized by hypnagogic (meaning the state between waking and sleeping) auditory hallucinations—in other words, sufferers hear things as they're drifting off to sleep. In the case of Exploding Head Syndrome, they're very loud things like shouting, crashing symbols, explosions and doors slamming.
Sufferers wake in a flurry of panic but luckily don't experience any pain, and aren't in any real danger. They do, however, often report an increased level of anxiety and fear of falling asleep.
Exploding Head Syndrome primarily affects women and older adults. The cause? Unknown.
2. REM sleep disorder
The sleep cycle is made up of REM (Rapid Eye Movement) and non-REM stages of sleep. During REM sleep, our body relaxes completely, while our brain is alert and active. This is when we dream.
With REM sleep disorder, the brain sends the wrong signals to the muscles. So, instead of relaxing, suffers of REM Sleep Disorder do the opposite, causing sufferers to act out their dreams.
The theatrical episodes don't generally last very long, but can be sudden and violent (think screaming, kicking and thrashing about), which means they can be harmful to sufferers and their unfortunate bed partners.
REM Sleep Disorder primarily affects men over 50 and anyone on high-dose anti-depressants. The cause? Also unknown.
3. Sleep Paralysis
On the other end of the REM sleep disorder spectrum, there's Sleep Paralysis. Here, the brain functions how it should during REM sleep, sending signals that keep muscles in a state of paralysis or relaxation. This is normal and we're usually not aware that it's even happening, but in a terrifying turn of events, sufferers of Sleep Paralysis wake up while their body is still paralysed.
The physical effects of being unable to move or speak are temporary, wearing off after just a few seconds to a few minutes. The accompanying terror sufferers feel can last longer, especially if the episodes are paired with hallucinations which they often are.
Sleep Paralysis can affect anyone. Causes include sleep deprivation, jet lag, narcolepsy, changing medications and certain psychiatric disorders.
4. Klein-Levin Syndrome (KLS)
AKA Sleeping Beauty Syndrome, this rare neurological disorder takes 'sleeping in' to a new level. Sufferers experience episodes of excessive sleep for between 12 and 24 hours at a time over a few days or even weeks.
During the episodes it's difficult to wake them, but when conscious, they'll often exhibit strange behaviours like a heightened sex drive, binge eating and even hallucinations. When it's all over, it's back to normal sleep patterns until the episodes kick-off again months later, without any warning.
Sufferers often live their life in a constant state of heightened anxiety, worrying that the next time they fall asleep, could be the start of another episode.
There is currently no definitive treatment, but usually the episodes peter out by themselves after around eight years.
Klein-Levin Syndrome primarily affects adolescent males. The cause is unknown.
5. Restless leg syndrome (RLS)
Restless leg syndrome can strike at any time but it's always worse at night, making falling asleep a tricky task.
Characterized by the almost irresistible urge to move your legs, sufferers describe symptoms of pulling, crawling, tingling, prickling and even pain as they're trying to fall asleep. Some even experience uncontrollable jerking movements of their legs at night. These feelings are often strong enough to cause sufferers to wake up multiple times a night, leading to other issues like sleeplessness and day time drowsiness.
Unlike other disorders on this list, RLS is largely controlled by targeting and treating the specific cause behind it. In most cases, moving the legs is enough to improve the symptoms.
Restless Leg Syndrome affects 2 - 5 per cent of men and women. Causes include low iron, too much caffeine, smoking and alcohol, health problems like anaemia, diabetes and arthritis, family history, pregnancy and nerve damage.
If you're having trouble sleeping, or if any of these sleep disorders feel a little too familiar, it can't hurt to book an appointment with your GP. They'll ask you questions and probably want to run some tests, or even refer you onto a sleep specialist.
With the help of your GP and a few great specialists, a good night's sleep may be just around the corner.