Understanding sleep

Why we need sleep

You spend about a third of your time asleep, so it forms a crucial part of your daily routine. It is an essential function, if you don’t get enough, your brain can’t function properly. Chronic lack of sleep, or getting poor quality sleep, increases the risk of disorders including cardiovascular disease, high blood pressure, diabetes, obesity and depression. Not getting enough sleep can have a major impact on your overall health, as well as your physical health it can affect your mental and emotional health. How positive, motivated and happy you feel during your waking hours can be directly affected by your previous night’s sleep.

Sleep science

There are two types of sleep, rapid eye movement (REM) sleep and non-REM sleep, which has three different stages. You cycle through all stages of non-REM and REM sleep several times during the night, with deeper REM periods occurring towards the morning.

Stage 1: Non-REM sleep is the shortest, lightest stage and forms the changeover from wakefulness to sleep, also known as the 'dozing off' stage. During this period your heartbeat, breathing, brain waves and eye movement slows, and your muscles relax.

Stage 2: The second non-REM sleep phase is a period of light sleep before you enter deeper sleep. Your body temperature drops, eye movements stop and your breathing and heart rate slow further. Brain wave activity slows, but the brain emits short bursts of activity, known as sleep spindles. Most people spend about half of their sleep time in this phase.

Stage 3: The third stage of non-REM sleep is the period is where your most restful, deep sleep occurs. All functions slow and relax further, ensuring that your body can recover and repair itself. It occurs in longer periods during the first half of the night and lasts for shorter periods as the night progresses. Non-REM sleep helps your body wind down and fall into a deep sleep, to help you feel more rested in the morning. It can help us physically heal, recover from illness, solve problems and deal with stress.

REM sleep occurs about 90 minutes after falling asleep, it is associated with dreaming and memory consolidation. During REM sleep, your eyes move rapidly behind your closed eye lids, your heart rate and blood pressure rises, you temporarily lose muscle tone and your breathing becomes irregular. Mixed frequency brain wave activity, also becomes closer to that seen in wakefulness. Most of your dreaming occurs during REM sleep, as you age, you sleep less of your time in the REM stage.

Two internal biological mechanisms - circadian rhythm and homeostasis, work together to regulate when you are awake and sleep.

Circadian rhythms are 24-hour cycles that are part of the body’s internal clock. They direct a wide variety of functions, including your sleep-wake cycle. Circadian rhythms synchronise with environmental cues such as light, and temperature. When this circadian rhythm is thrown off, it can create significant sleeping problems, including insomnia. Exposure to natural light, especially early in the day, and limiting artificial light exposure at night helps reinforce this strongest circadian cue.

Sleep-wake homeostasis keeps track of your need for sleep. The pressure that calls us to our beds is exerted through the manipulation of neurological substances in the brain. Stress, your sleep environment and what you eat and drink can be influences, but the greatest influence is the exposure to light. Cells in the retina of your eye process light and tell your brain whether it is day or night, this can advance or delay our sleep-wake cycle. Night shift workers and those with jet lag, often suffer as circadian rhythms become out of sync, creating a mismatch between their internal clock and the actual clock.

Sleep problems

The collective term 'sleep disorder' refers to conditions that affect sleep timing, quality or duration, and impact someone’s ability to function properly whilst awake. More than 100 specific sleep disorders have been identified. One of the most common conditions is insomnia, up to one third of adults suffer from it. Insomnia is characterised regular difficulty falling or remaining asleep. It is considered a chronic condition when patients exhibit symptoms at least three times per week for at least three months. Insomnia can be triggered by many things, including stress, anxiety, a poor sleeping environment, as well as mental and physical health conditions. We encourage people who experience any of these conditions to consult with their doctor.

Help sleeping

Getting enough sleep is good for your health, most adults need between six and nine hours of sleep every night. Winding down and relaxing before bed is a crucial stage in the sleep process, here are a few tips that could help improve your sleep:

• Keep regular sleeping hours, this programmes the brain and internal body clock to get used to a set routine. If you’ve had a disrupted night’s sleep, try not to catch up on sleep by getting up later, doing so on a regular basis can also disrupt your sleep routine.
• In the evening try to avoid alcohol as it can be sleep disturbing, instead reach for a caffeine free herbal tea that contains valerian.
• Take a warm bath with a relaxing, essential oil based bath foam or bath salts.
• Do a little yoga or stretching to help to relax your body and mind, try to keep vigorous exercise to the morning.
• Keep your bedroom as clutter free as possible so that it is an enjoyable place to relax in. Pay particular attention to your bedding, a fabric like bamboo is soft, skin friendly and heat regulating. Your room should also be as dark as possible, try fitting black out blinds and wearing a sleep mask. Scents also play a key role in signalling to our brain that it is time to rest, try a candle, diffuser or pillow spray with an essential blend of lavender, geranium and bergamot.
• Keep a notepad beside your bed to write your to do list for the next day, plus anything that is on your mind. If you wake in the night you can also use it to write down ideas or worries, helping clear your mind of any distractions.
• Play some relaxing music or guided sleep meditations, if you live somewhere with a lot of background or road noise, white noise can be beneficial.
• Avoid using your mobile phone or other electronic devices at least an hour before bed. They can stimulate your mind and the blue light they emit has been linked to sleep disruption. Instead read a book or listen to an audio book.
• If you wake in the night, don’t lie in bed awake or scroll on your phone, if you can’t get back to sleep, do something else, like reading or listening to music until you feel tired.