4 Sleep Stages

The 4 stages of the sleep cycle:

Stage 1: is where one enters light sleep. This stage of the sleep cycle is distinct by Non-rapid eye movements (NREM). At this stage of the sleep cycle, one’s body temperature as well as heartbeat will decrease, preparing one for deeper sleep.

Stage 2: We enter deeper sleep now. Similar to stage 1 of the sleep cycle, in this stage of the sleep cycle, one’s body temperature and heartbeat decrease further. It is also distinct by NREM. Furthermore, brainwaves will also decrease (delta waves) and our muscle will relax. Here, our body starts to restore itself, hormones are released and our body is well rested.

Stage 3: Like stage 1 and 2 of the sleep cycle, this is a NREM stage too. However, in this stage of the sleep cycle, we have already entered deep sleep also known as delta sleep. And the slow brainwaves are replaced with quicker ones. It is hard to wake someone up when one is in delta sleep.

Stage 4: Similar to stage 3 of the sleep cycle, in this stage of the sleep cycle, we are in delta sleep. However, instead of NREM, REM occurs where our eyes move rapidly. Conversely, our heartbeat increase, blood pressure increases as well. Muscles become immobilized. Most dreams occurs here, hence if one are awaken in this stage of the sleep cycle, one is more likely to remember the details of the dream.

When does dream occurs in our sleep cycle?

One can dream in any of the 4 stages of the sleep cycle. However, one can only what he dream if he is awaken at the 4th stage of the sleep cycle where the dream is the most concrete. Since one sleep around 8 hours each night, we undergo 4 to 5 sleep cycles, hence it is common for one to have many dreams in one night. Even so, most people only remember the very last dream.