Sleep paralysis is a condition recognized in many cultures. It is the inability to move the muscles when waking up from sleep. Almost every country has its own definitions in the language of the people. It has been given various names such as witch’s raid, nightmare, witch visit, mora, painajainen.
In healthy individuals, there is a rhythm called the circadian rhythm, in which the timing and duration of sleep and wakefulness are adjusted by the body. This determines the starting and ending points of the person’s sleep. Suprachiasmatic nucleus point is responsible for this rhythm in the brain. Sunlight, stress factors, melatonin and serotonin are the determining factors for this rhythm.
Sleep is considered a two-phase cycle. These stages are REM and Non-REM stages. The non-REM phase can also be described as the preparation phase of the body during the sleep initiation phase. Then the body enters the REM phase. These two phases repeat approximately every 90-120 minutes. In young adults, the NREM phase is 75% and the REM phase is 25% in one cycle. In the elderly, both are seen to decrease.
In the NREM stage, the transition to sleep begins. The blood pressure in the body is partially reduced and the body temperature drops, the muscles begin to relax, the heart rate is calm and slow. In this phase, the eyes are closed and motionless. Thus, deep sleep is achieved. After this stage, the REM sleep stage begins. During REM sleep, where most dreams occur, the brain becomes active. In REM sleep, the eyes move quickly even though they are closed. By sending signals to voluntary muscles such as arms and legs by the brain, they are prevented from contracting, and the body is completely relaxed and immobilized. This state of the body is called muscle atony.
Muscle atony is a normal process of REM sleep. Its main purpose is to prevent any injury that may occur due to the effect of dreams during REM sleep. Sometimes, when you are in a deep sleep, you may be able to observe the surroundings with your eyes when you suddenly wake up. In these situations, there may be moments when you can hear the sounds around you but cannot move. This condition is called sleep paralysis. Sleep paralysis is the state of muscle atony that the brain provides while asleep, and continues for a while when you wake up.
Muscle atony is not felt during normal sleep. However, waking up before REM sleep is complete or during the transition to this stage causes sleep paralysis.
A person with sleep paralysis may experience hallucinations from time to time. He may even feel as if he is out of breath or as if there is pressure in his chest. This may take a few seconds or a few minutes.
Insomnia or disrupted sleep patterns can make it easier to experience sleep paralysis. In addition, conditions such as stress or post-traumatic stress disorder, depression, anxiety, or bipolar disorder can also cause sleep paralysis. Those with these conditions are at increased risk for sleep paralysis. From time to time, sudden changes in lifestyle or location, or using sleeping pills can also trigger sleep paralysis.
Sleep paralysis is normally rare, temporary and does not cause significant health problems. But frequent sufferers are advised to see a doctor. No death reports due to sleep paralysis have been recorded so far.
It has been observed that meditation and relaxation therapies are beneficial in treatment applications due to sleep paralysis.