After a night of no sleep, everyone feels dreadful. Whatever caused the sleepless night, the day after is awful for everybody who has experienced insomnia.
The next day headaches, nausea and body aches are grim realities. And you probably look terrible.
We often take sleep for granted, but when we don’t get enough, we realise how important it is. Sleep affects our day-to-day performance and your physical and mental health in many ways. But have you ever wondered exactly why is it that you feel so awful after a sleepless night?
Things that happen in your sleep
Our natural sleep patterns are controlled by an internal body clock called a "circadian clock" that regulates body temperature, hormone levels, heart rate and other vital bodily functions.
While you're asleep, you're actively restoring fundamental chemical balance – all in preparation for a new day, and a fresh start.
Sleep also keeps electrical currents flowing and essentially recharges your batteries, so if you haven’t been sleeping, its little wonder you feel so awful. Your body can't function without sleep – and shutting down is its way of trying to tell you this.
Why the insomnia hangover?
The day after a sleepless night, people often experience heart palpitations, nausea, dizziness or light-headedness.
"It's because your Cortisol levels are disrupted when you don’t sleep properly," says Dr Moyra Stein, Cape Town general practitioner. Cortisol is an important hormone that helps to regulate blood pressure and metabolism.
"Not sleeping invariably affects your heart rate. When we sleep, we are relaxed and our pulse and breathing slows down. Not sleeping means that no slowing down or relaxation occurs, and you're left in a very anxious type of space."
When you fail to sleep, your eyes also aren’t lubricated, and they feel scratchy the next day as a result of it.
"When we're awake, our bodies are tense, and tensed-up," says Dr Stein. "Being awake repeatedly will eventually take its toll on the body. The muscles have no chance to relax and only in sleep are we truly relaxed."
Why the long face?
But feeling wiped out is not all you have to cope with after a sleepless night. You probably look terrible, as well.
"Your grey complexion is the result of poor circulation," says Dr Stein. " Sleep improves our blood flow, and our blood doesn’t flow properly if we've been strtessed out at night," says Dr Stein.
Sleep most certainly improves skin appearance, because when we sleep, our cells restore themselves. "Beauty sleep" is not such as a far-fetched idea, after all.
Sitting on a time bomb
Your irritation threshold is particularly low if you're sleep-deprived. This is because sleeping is a time for restoring mental energy and if it's not restored, you won't be able to think properly, and will, in all probability, make irrational decisions.
Studies show that sleep deprivation also negatively alters brain activity, slowing reaction time in certain cellular and chemical activities as well as slowing you down. No wonder you feel unable to concentrate.
Lack of sleep also makes it difficult to focus the eyes effectively as you can do when you are well rested, so if you find you suffer from headaches after a sleepless night, it's probably because you're struggling to see.
The bottom line is that when your body is not properly rested, it can't function as it should. And every motion requires extra effort, which tires your body out even more.
So do yourself a favour - when you get home tonight, draw a herbal bath, listen to some soothing music, light a candle, climb into bed and breathe deeply before you get into bed for a decent night's sleep. You owe it to your body, to yourself and to all those around you.
Read these fascinating sleep facts.
(Tori Foxcroft, updated by Health24 June 2012)