Seventy years ago, scientists had a poor understanding of what happened when people fell asleep. They believed that the body and brain shut down, entering a passive phase that allowed people to recover. Research has revealed that sleep is much more complex than was previously thought and is also much more active. When you fall asleep, your brain goes through several stages during which different types of activity occur. Your brain moves through the different stages of sleep in a predictable cycle between non-REM and REM sleep. Understanding the different sleep cycles and how they impact the quality of your sleep is important.
Phase one of sleep
Within a few minutes of when you fall asleep, the movement of your eyes slows. Your brain will begin producing theta and alpha waves during this phase. Phase one of sleeping is fairly brief and lasts approximately seven minutes. During this introductory sleep period, you are sleeping lightly and can be easily awakened. This is the type of sleep that many people get when they take brief naps during the day.
Phase two of sleep
Phase two of sleep is still a lighter stage. During this phase, your brain produces increases in the frequency of your brain waves, which are called sleep spindles. After the production of sleep spindles, your brain waves will slow. People who take longer naps during the day would want to awaken after completing phase two of sleep.
Phases three and four of sleep
Phase three of sleep is the start of deep sleep. Your brain will start to produce delta waves, which are slower brain waves. During this phase, you will not have any eye movements or muscular activity. It will be more difficult for others to awaken you during phase three. Your body will have reduced responsiveness to external stimuli. As you move into phase four of sleep, your brain will produce an increased number of delta waves. Phase four is the deepest level of sleep and is a period of restoration for your body. It is the hardest to awaken people in phase four of sleep. During this phase, your body will repair tissues and muscles, boost the functioning of your immune system, stimulate development and growth, and build up your energy reserves for the following day.
REM or rapid eye movement sleep
Rapid eye movement or REM sleep is a stage of sleep that you normally enter approximately 90 minutes after you first fall asleep. Each stage of REM sleep can last up to 60 minutes. On average, an adult will go through five or six REM cycles every night. REM sleep is the final phase of sleep, and your brain will become more active. REM sleep is when most people experience dreams. Your eyes will move rapidly in different directions. Your blood pressure, heart rate, and breathing increase. REM sleep is important for memory and learning. During this phase of sleep, your brain processes information from the previous day to store it in your long-term memory.
The length of each sleep phase differs depending on your age. For example, an elderly person’s sleep cycles will be different than those of an infant. You normally move through the various phases of sleep sequentially. Most of your non-REM sleep will happen early in the night. The length of your REM sleep will increase as the night progresses. This is why people often awaken in the morning from dreams.
Get help from Accent Sleep Solutions
If you suffer from sleep problems, something might be interrupting your natural sleep cycles. Dr. Jeffrey M. Phillips at Accent Sleep Solutions in Gainesville, Florida can help you to identify what is causing your sleep problems so that the underlying issue can be treated. Getting good-quality sleep is important for your health and well-being. Contact us today to schedule an appointment by calling us at (352) 271-5375.