卒魇者，屈也，谓梦里为鬼邪之所魇屈。人卧不悟，皆是魂魄外游，为他邪所执录，欲
还未得，致成魇也。忌火照，火照则神魂遂不复入，乃至于死。而人有于灯光前魇者，是本
由明出，是以不忌火也。
又云∶人魇，忽然明唤之，魇死不疑。暗唤之好。唯得远唤，亦不得近而急唤，亦喜失魂
魄也。其汤熨针石，别有正方，补养宣导，今附于后。
《养生方·导引法》云∶拘魂门，制魄户，名曰握固法。屈大母指，着四小指内抱之，
积习不止，眠时亦不复开，令人不魇魅。
人眠睡，则魂魄外游，为鬼邪所魇屈。其精神弱者，魇则久不得寤，乃至气暴绝。所以
须傍人助唤，并以方术治之，乃苏。
人有不得意志者，多生忿恨，往往自缢，以绳物系颈，自悬挂致死，呼为自缢。若觉早
，虽已死，徐徐捧下，其阴阳经络虽暴壅闭，而脏腑真气故有未尽，所以犹可救疗，故有得
活者。若见其悬挂，便忽遽截断其绳，旧云则不可救。此言气已壅闭，绳忽暴断，其气虽通
，而奔迸运闷故，则气不能还，即不得复生。
又云∶自缢死，旦至暮，虽已冷，必可治；暮至旦，则难治。此谓其昼则阳盛，其气易
通；夜则阴盛，其气难通。
又云∶夏则夜短，又热，则易活。
又云∶气虽已断，而心微温者，一日以上，犹可活也。
卒魇（突然被鬼压床或梦魇），是指“屈”的意思，即指在梦中受到鬼邪的压迫和束缚。人睡眠时意识不清醒，都是因为魂魄向外游荡，被其他邪气所拘捕，想要回来却回不来，从而导致了魇症。忌讳用火光照耀，因为火照会使神魂不再返回体内，甚至导致死亡。但是有人在灯光前发生魇症的情况，是因为原本就是由光亮引起的，所以不忌讳火光。
又有人说：人发生魇症时，如果突然大声呼唤他，会导致其死亡而不可挽回；如果在暗中轻声呼唤则有益。只适合远距离呼唤，也不得靠近并急促地呼唤，因为这也会使人的魂魄丢失。至于汤药、热敷、针刺、砭石等治疗方法，另有专门的方剂，补益调养和导引宣通的方法，现在附在后面。
《养生方·导引法》中说：拘魂门，制魄户，这种方法叫做握固法。弯曲大拇指，扣在四个小指里面抱住，长期练习不停止，睡觉时也不再松开，可以让人不被鬼魅侵扰。
人进入睡眠状态时，魂魄就会向外游荡，被鬼邪压迫束缚。精神虚弱的人，发生魇症后很久都不能醒来，甚至导致气息突然断绝。所以需要旁边的人帮助呼唤，并用方术来治疗，才能苏醒。
有的人意志不得志，常常产生忿恨情绪，往往选择自缢，用绳子或其他物品系住脖子，自己悬挂起来致死，称为自缢。如果察觉得早，虽然已经死亡，慢慢将其放下，虽然阴阳经络突然闭塞阻滞，但脏腑的真气还没有完全耗尽，所以还可以救治，因此有存活下来的案例。如果看到人悬挂，就匆忙切断绳子，旧时说这样就不能救治了。这是因为气已经闭塞阻滞，绳子突然暴断，虽然气通了，但因为气机奔迸冲撞导致闷乱，气不能回归原位，立即就无法再生还。
又说：自缢死亡，从早晨到傍晚，虽然身体已经变冷，必定可以救治；从傍晚到早晨，就很难救治了。这是说白天阳气旺盛，气容易通畅；夜晚阴气旺盛，气难以通畅。
又说：夏天夜晚短，天气又热，则容易救活。
又说：气息虽然已经断绝，但心脏部位还有微温的，超过一天以上，仍然可以救活。
Sudden Yan (sudden sleep paralysis or nightmare), refers to "qu" (constraint), meaning being oppressed and bound by demonic evils in dreams. When a person sleeps without awareness, it is because the Hun (ethereal soul) and Po (corporeal soul) wander outside, are captured by other pathogenic factors, wish to return but cannot, thus resulting in Yan syndrome. It is taboo to illuminate with fire, as fire illumination causes the spirit and soul to fail to re-enter the body, potentially leading to death. However, for those who experience Yan under lamplight, since the cause originates from brightness, fire illumination is not taboo.
It is also said: When a person suffers from Yan, suddenly calling out loudly will undoubtedly cause death; calling softly in the dark is beneficial. One should only call from a distance, and must not call urgently while close, as this may also cause the loss of Hun and Po. Regarding treatments involving decoctions, hot compresses, acupuncture, and stone therapy, there are separate specific formulas. Methods for tonifying, nourishing, promoting circulation, and guiding qi are attached below.
The *Yangsheng Fang · Daoyin Fa* states: Constrain the Hun Gate, control the Po Door; this method is called the "Grasping Solid" technique. Bend the thumb inward, holding it within the four smaller fingers. If practiced continuously over time, even during sleep the hands remain closed, preventing people from being disturbed by demonic influences.
When humans enter sleep, the Hun and Po wander outward and are oppressed by demonic evils. Those with weak spirit and essence, when suffering from Yan, may remain unconscious for a long time, even to the point of sudden cessation of Qi. Therefore, assistance from others to call out is necessary, and treatment with medical arts is required for recovery.
Individuals whose will is unfulfilled often generate resentment and anger, frequently committing suicide by hanging themselves with ropes or other objects around their necks, known as suicide by hanging. If discovered early, even if clinically dead, slowly lowering them down allows for rescue; although the Yin and Yang meridians are suddenly blocked, the true Qi of the Zang-Fu organs has not yet completely exhausted, so treatment is still possible, and survival occurs. If one sees a hanging body and hastily cuts the rope, old texts state this makes rescue impossible. This is because the Qi is already blocked; the sudden breaking of the rope causes the Qi to rush and become chaotic, preventing it from returning to its proper place, thus making revival impossible.
It is also said: Suicide by hanging occurring from morning to evening, even if the body is cold, can certainly be treated; occurring from evening to morning is difficult to treat. This is because Yang Qi is abundant during the day, making Qi flow easier to restore; whereas Yin Qi is abundant at night, making Qi flow harder to restore.
It is also said: In summer, nights are short and temperatures are high, making resuscitation easier.
It is also said: Even if breathing has ceased, if the heart region remains slightly warm, revival is still possible after more than one day.