You’re probably familiar with our own body clock. You know the feeling when you’ve got the chance to have an extra hour in bed but you still wake up at the usual time. Or, you’re at a party that’s still in full swing and you can barely keep your eyes open.
That’s your 'body clock' at work. It’s the result of the Circadian Rhythm, the cycle of night and day in any twenty-four hour period and it also affects your body temperature, blood pressure, digestive secretions and hormone production.
Your circadian rhythm is controlled by the hypothalamus in the brain, which is near to the optic nerve and explains why your sleep is so affected by light. Your sleep is controlled by neurotransmitters, which act on nerves in the brainstem and the spinal cord.
Your cycle of sleeping and being awake depends on ambient light and temperature and changes to them will affect that cycle. Other factors can also affect your cycle, things like alarms, changes to your normal mealtimes, pressure and stress at work or financial worries can all take their toll.
Body Clock Problems
Disruption of your Circadian Rhythm can cause numerous problems like Jet Lag, Delayed Sleep Phase Syndrome (DSPS), which creates a need to sleep longer and Advanced Sleep Phase Syndrome (ASPS), which is the exact opposite and creates the need to go to bed early early and wake early. As children grow into teenagers and adjust to their circadian rhythm, they start to sleep and wake later, eventually adjusting fully to their adult sleep pattern.
For DSPS sufferers this pattern continues to develop and they will have a distinct preference for going to bed later than normal and also rising later than normal. Should they wake early, for whatever reason, they will remain 'drowsy' for several hours and suffer from loss of sleep.
Nightshift workers often find it difficult to readjust to normal night sleeping but are usually are able to get back to normal after a couple of weeks or so. For some, however, the sleep disruption continues for longer.
Jet lag is, generally speaking, a temporary problem with the body clock adjusting back to its normal rhythm after a few days or up to a week, the greater the time difference the longer the time it takes. For some, these disruptions cause very few problems while others find it difficult to adjust.
ASPS is, more or less, the exact opposite to DSPS with sufferers constantly needing an early night and rising bright and breezy early each morning and acute sufferers finding it hard to get any sleep at all after 3 or 4 am. It’s a condition that is most common in older people who will frequently compensate for their early waking by taking a nap in the afternoon.
Although daylight, or lack of it, is the most powerful influence on when we sleep, there are other influences that affect our sleep patterns. Our relationships, our education, our work all demand constant adaptation of our circadian rhythm. If we were able to sleep wherever and whenever we feel like it the world around us would find it almost impossible to function.
We are, for the most part, able to cope with disruptions like a foreign holiday or growing up, but for some people, adjustment is harder and the problem persists, which could mean they have a Circadian Disorder.
Usually a progressive adjustment to normal sleeping times can be achieved by gradually changing the time of going to bed and waking and, by gently doing this over a period of weeks, the body clock adjusts to normal waking and sleeping.
Melatonin, produced in the pineal gland of the brain during the night and ceasing as daylight approaches, affects our body clock throughout our lives and melatonin supplements, available only on prescription in this country, are often used to help people who suffer from sleep problems. Bright Light Therapy, which affects the production of melatonin, can also be used to help correct body clock disorders.
When your body clock is affected by events such as work or long haul travel, re-establishing a regular routine is often enough to identify your normal 'rhythm' and get your sleeping patterns back to normal.