Stage 4: very deep sleepshe is quiet and does not move. Stage 3: deep sleepyour baby is quiet and does not move. Stage 2: light sleepyour baby moves and may startle or jump with sounds. Teens and individuals under age 30 tend to spend the most time in deep-sleep stages. Stage 1: drowsinesseyes droop, may open and close, dozing. The amount of time spent in each state and stage of sleep varies and can change over time. The last period of REM sleep may last for approximately an hour. As the cycle repeats, each period of REM sleep is longer than the prior period. The arms and legs become immobile or temporarily paralyzed.Īfter each REM state, the body cycles back to an NREM state. REM sleep is the state in which dreams are most likely to occur due to heightened brain activity. During this state, heart rate and blood pressure increase and breathing quickens. The first period of REM sleep is reached about 90 minutes after falling asleep and lasts for approximately 10 minutes. Rapid eye movement (REM) sleep gets its name from the quick movement of the eyes (behind closed eyelids) that occur during this state of sleep. Deep sleep is also when memories are consolidated and learning and emotions are processed.Īfter stage 4, cycling between stage 3 and stage 2 occurs until REM sleep is achieved. During this stage, the body strengthens the immune system, builds bone and muscle, and repairs tissues. Deep sleep is also known as slow-wave or delta sleep. If an individual does wake up, they may feel disoriented. A person in deep sleep is more difficult to wake up. During deep sleep, breathing, heart rate, and body temperature reach their lowest levels. Stage 3 is the first deep-sleep stage.

The CPU stays in deep C4 state longer, resulting in lower power consumption while idle. Deeper sleep comes from improvements in CPU and chipset interaction to redirect snoop cycles. This is because they spent enough time alternating through the deep sleep stages while the light sleeper did not. Heavy sleepers may sleep a significantly shorter amount of time than light sleepers, but wake feeling better rested. This prepares the body and brain to enter deep sleep in stages 3 and 4. C3 deep sleep and C4 deeper sleep are ACPI power management states. However, the amount of time you rest does not always determine whether or not you got enough sleep. During this stage, breathing slows down, heart rate and body temperature decrease, and the muscles relax. Stage 2 is the second stage of light sleep.Twitching may occur as the body transitions to stage 2. The eyes are closed, but an individual in this stage of sleep can be easily awakened. Each stage typically lasts five to 15 minutes. Non-rapid eye movement is the first state of sleep that occurs immediately after falling asleep. The mind and body cycle through these states and stages throughout the night. Deep sleep also promotes immune system functioning. During deep sleep, your body releases growth hormone and works to build and repair muscles, bones, and tissue. Within NREM sleep, there are four different stages. While all stages of sleep are necessary for good health, deep sleep offers specific physical and mental benefits. Sleep consists of two different states: rapid eye movement (REM) sleep and non-rapid eye movement (NREM) sleep.

Light vs deep sleep