What ‘Normal Sleep’ Really Looks Like

Sleep is a vital component of our overall health and well-being, yet many of us take it for granted until we encounter problems.

Understanding the normal process of sleep can help us appreciate its importance and recognise when something might be wrong. This post explores the intricacies of sleep cycles, their functions, and explains what constitutes 'normal sleep', distinguishing it from conditions such as insomnia.

If you suspect that your sleep patterns deviate from the norm, it’s crucial to consult with a sleep professional.

The Architecture of Sleep

Sleep is a complex, active process that can be divided into two main types: Non-Rapid Eye Movement (NREM) sleep and Rapid Eye Movement (REM) sleep. Together, these form a sleep cycle, and an average night’s sleep includes multiple cycles, each lasting about 90 to 110 minutes. Here’s a closer look at the stages:

1. NREM Sleep

• Stage 1: This is the lightest stage of sleep, lasting only 5-10 minutes. During this phase, you transition from wakefulness to sleep. Your muscle activity slows down, and you may experience sudden muscle contractions followed by relaxation, often referred to as hypnic jerks.

• Stage 2: In this stage, body temperature drops and heart rate slows, and you become disengaged from your surroundings. It lasts around 20 minutes.

• Stage 3: A deeper sleep stage - also known as slow-wave sleep (SWS), this stage is crucial for physical restoration and recovery. Your muscles relax, your blood pressure drops and your body is able to repair tissue, build bone and muscle, and strengthens the immune system. Slow brain waves, known as delta waves, dominate this stage, lasting 20-40 minutes.

• Stage 4: Even deeper sleep - Rapid Eye Movement (REM) sleep...
  

2. REM Sleep (or Stage 4)

• REM Sleep: This stage first occurs about 90 minutes after falling asleep and recurs every 90 minutes. REM sleep is characterised by rapid movements of the eyes, vivid dreams, and increased brain activity, almost resembling wakefulness. During REM, your muscles are temporarily paralysed to prevent acting out dreams. This stage is critical for cognitive functions such as memory, learning, and emotional regulation. This is also where some 'emotional first aid' occurs, as well as a boost of creativity. That sounds crazy to have that when you're unconscious, but it helps with solutions to problems that you may have when you're awake.
  

The Importance of Sleep Cycles

Each stage of sleep serves a unique function, and cycling through these stages multiple times a night is essential for optimal health. Here’s why these cycles matter:

• Physical Health: Deep NREM sleep (Stage 3) is vital for physical restoration. Growth hormone, which is essential for tissue growth and muscle repair, is released during this stage. A lack of deep sleep can impair immune function, increase inflammation, and contribute to chronic conditions like hypertension and diabetes.

• Cognitive Function: REM sleep enhances cognitive functions, including memory consolidation, problem-solving, and creativity. Studies have shown that people who get adequate REM sleep perform better on tasks requiring complex thought and emotional regulation.

• Emotional Well-being: Both NREM and REM sleep are crucial for processing and regulating emotions. During sleep, the brain processes emotional experiences from the day, which helps maintain emotional stability. Insufficient sleep can lead to mood disorders, anxiety, and depression.

The Ratio is Important!

It's not just about how many hours your getting, or how many sleep cycles you complete. It's essential to know the ratios as well.

In the earlier part of the night, REM sleep may only last about 10 minutes. Not a lot of dreaming and problems solving occurring or memory consolidation here. But, but the early hours of the morning, REM can last for up to an hour! So when sleep is 'normal', you can expect more physical restoration in the first half of the night, and more cognitive restoration in the second half of the night.

When I speak to clients about their sleep, I need to know the timing details about their sleep. For example, if someone is falling asleep OK, but waking very early (e.g. 2am) and having disrupted sleep from then on, there is a significant loss in REM sleep, which can be problematic for their cognitive functioning and emotional regulation. They are not only tired from less overall sleep, but they are often less emotionally resilient.

Recognising Abnormal Sleep Patterns

The normal process of sleep is highly structured, so any significant movement away from this pattern may indicate a sleep disorder, like insomnia. Insomnia is characterised by difficulty falling asleep, staying asleep, or waking up too early and not being able to return to sleep. It leads to daytime impairment and distress, affecting mood, energy, and overall quality of life.

Signs that your sleep may not be normal include:

• Difficulty falling asleep: Spending more than 30 minutes trying to fall asleep regularly.

• Frequent awakenings: Waking up multiple times during the night and having trouble falling back asleep.

• Early morning awakenings: Consistently waking up earlier than desired and being unable to return to sleep.

• Non-restorative sleep: Feeling unrefreshed and tired despite having spent an adequate amount of time in bed.

I wish more people knew about what sleep involves! If you recognise any of these symptoms in your own sleep patterns, it’s important to seek help. Chronic insomnia not only affects your daily functioning but can also have long-term health consequences.

Consulting a sleep professional can provide you with a proper diagnosis and effective treatment options. Cognitive behavioural therapy for insomnia (CBT-I) and certain medications can be highly effective in managing and improving sleep quality ☺