Sleep is an incredibly important biological process that relies on various organ systems and neurological processes. To put it simply, sleep provides essential nutrition for the brain.
But when issues with sleep arise, this imperative process can be compromised.
The most common sleep disorder, insomnia, poses a large, often long-term threat to the quality of life of those suffering with the condition.
Insomnia is characterized by issues with sleep, which can manifest in different ways.
To understand how insomnia can be caused, it is important to consider these different manifestations in closer detail.
1. Sleep Onset Insomnia (SOI)
“I find it hard to get to sleep.”
You might be familiar with the above statement, and that’s because SOI is the most common and most recognised form of insomnia; a struggle or inability to fall asleep.
The most common causes of SOI include:
- High stress levels. Cortisol, a stress hormone, is a stimulant that causes hyperactivity in the brain. Lowering stress can reduce cortisol levels in the body and promote a healthier sleep schedule.
- Irregular circadian rhythm. The circadian rhythm, controlled by our cortisol and melatonin hormones, is what makes us feel awake in the morning and throughout the day, as well as making us feel tired in the evening. If the circadian rhythm becomes irregular due to travel, stress or shift work, this can lead to insomnia.
- Side effects of medications. Many medications include stimulants such as caffeine, Ritalin or Ventolin, which can alter the body’s sleep cycle.
2. Sleep Maintenance Insomnia (SMI)
“I find it hard to stay asleep.”
You may find this sentence familiar. If you experience this often, then you could be living with SMI. Sleep maintenance insomnia causes sufferers to wake up mid-sleep, often at the same time every night.
The most common causes of SMI include:
- Blood sugar dysregulation. While we sleep, our bodies are not consuming any food. This causes blood sugar levels to drop low, but if they drop too low then the body can panic and force us to wake up. People that experience blood sugar dysregulation leading to SMI often feel hungry when they wake up for this reason.
- Sleep apnoea. Sleep apnoea is a very serious condition that causes irregular breathing patterns during sleep and is characterized by pauses in breathing, during which time the brain is momentarily starved of oxygen and forces us to wake up suddenly. If you believe you may have sleep apnoea it is vitally important to seek medical help as soon as possible.
- Another potential cause of SMI is irregular circadian rhythm.
3. Non-Restorative Insomnia (NRI)
“I don’t feel refreshed in the morning.”
Non-restorative insomnia is the term used to describe a condition leaving the sufferer feeling just as tired as before they had had a full night sleep. Those with the condition will often wake up feeling that they have not slept at all.
The condition comes with other, daytime symptoms, often associated with insomnia in general. Those with NRI will often experience the same irritable mood and fatigue as SMI and SOI sufferers.
The most common causes of NRI include blood sugar dysregulation (see above) and restless leg syndrome, which involves a constant need to move or be on-the-go.
