Stages of Sleep - Do you know yours?

I think this is maybe the number one complaint I see in my office! Difficulty with sleep, whether it's a newborn baby, a perimenopausal women or elderly gentleman.

A good night's sleep is crucial for overall health and well-being. But sleep is complex and it involves several distinct stages, each with its own unique characteristics and benefits. 

1. Stage 1 Sleep (N1): This is the lightest stage of sleep and typically lasts for a few minutes. During this stage, you may experience drifting in and out of sleep, and your brain produces theta waves. It's easy to be awakened from stage 1 sleep, and it usually constitutes a small percentage of the total sleep time, around 5%.
2. Stage 2 Sleep (N2): Here the body starts to prepare for deeper sleep. It makes up the majority of the sleep cycle, comprising about 50-60% of the total sleep time. During stage 2 sleep, brain activity slows down, and you experience bursts of rapid eye movement (REM) sleep. It's also characterized by the presence of sleep spindles and K-complexes, which are believed to play a role in memory consolidation.
3. Stage 3 Sleep (N3): This is the beginning of deep sleep, also known as slow-wave sleep (SWS) or delta sleep. It's a critical stage for physical restoration and growth, as well as for immune function. During stage 3 sleep, your brain produces slow delta waves, and it's harder to be awakened. Stage 3 sleep typically accounts for about 20-25% of the total sleep time in healthy adults.
4. Stage 4 Sleep (N3): This is the deepest and most restorative stage of sleep, also known as delta sleep or slow-wave sleep (SWS). During stage 4 sleep, your brain produces predominantly delta waves, and it's difficult to be awakened. This stage is essential for physical restoration, including muscle and tissue repair, hormone regulation, and memory consolidation. Stage 4 sleep usually occurs earlier in the night and may account for about 10-15% of the total sleep time in healthy adults.
5. Rapid Eye Movement (REM) Sleep: REM sleep is a unique stage of sleep characterized by rapid eye movements, increased brain activity, and vivid dreaming. REM sleep is important for cognitive function, memory consolidation, emotional regulation, and learning. REM sleep typically occurs in cycles throughout the night, and it accounts for about 20-25% of the total sleep time in healthy adults.

It's important to note that the recommended amounts of each sleep stage may vary depending on age, individual differences, and other factors. But a general guideline for adults is to aim for around 20-25% of total sleep time in REM sleep, and around 60-70% of total sleep time in non-REM sleep (stages 1, 2, 3, and 4 combined), with stage 3 and 4 sleep (deep sleep) comprising about 20-25% of total sleep time.

Sleep Cycle Order

Generally you should go through 4 to 6 sleep cycles of

- Wake, light sleep, deep sleep, REM, and repeat.

Cycles earlier in the night tend to have more deep sleep while later cycles have a higher proportion of REM. By the final cycle, your body may even choose to skip deep sleep altogether.

I think it is critical people know how much and what kind of sleep they are actually getting! How can you improve something you can't measure or monitor? It's a good place to start.