I was reading that the Zen monk Hakuin suffered a debilitating condition called zen sickness before his enlightenment. This seem to be a direct result of his practice.

Does anyone know what this was? Has there been a retrospective medical diagnosis of this? Are there equivalent stages of the path in other traditions? Should I be worried?



7 Answers 7


I have done some research online and read articles about zen sickness.

There are a couple of problems when doing research, online, on an ailment which, can be "bearing" on enlightenment, because there are lots of "me too is having this ailment", in other words "I too, am close to being enlightened"; And suddenly, zen sickness symptoms multiplied: psychological depersonalisation, etc.. are linked to zen sickness and the definition of zen sickness becomes vague and fuzzy.

Even when I confine my readings to only very few recorded accomplished zen/chan masters, who actually do intensive meditations, their descriptions of zen sickness differ, and that is perhaps due to incorrect attribution ( the "me too" phenomena) of an experience to zen sickness. (I decided, eventually, not to provide links because it would create more confusion/debate on it, so don't take my word on it).

The zen sickness of Master Han Shan, IMHO, seems to be a genuine description, but I don't agree to some of the discussion, especially the last but one paragraph which begins with:

The situation of Zen sickness is not something you should desire, and certainly not something you want to force into occurring. Since it is a trouble or affliction, you want to avoid it if you can, but the important thing is that there is a remedy if it occurs. Think of it in terms of ....

It is not something you can force or get into easily unless you want to reprogram your own mind, but that's my view.

Theravada Tradition

From my reading and analysis it would correspond to an Anagami in the Theravada tradition working towards Arahatship, where at that stage the most prominent problem is restlessness.

IMHO, at the path stage of an Anagami it has seen emptiness clearly and enjoys the bliss of holding onto emptiness. To get to the fruit of Anagami it has to let go of that hold on emptiness. Once it has decided to let go of emptiness the bliss, vanished. The bliss makes the mind concentrated, I quote "the purpose of bliss is concentration"(.. in some sutta).

With the letting go of emptiness & bliss the mind will just grab at any thought,tune,occupations to concentrate the mind, because if it didn't, the restlessness of the mind is unbearable( we are here talking about a very sensitive fine mind; restlessness is one of the last five fetters ).

Why then can not an Anagami phala(phala sounds better than fruit, which reminds me of fruitcake) go back to holding onto emptiness again and get the bliss back? The answer is that it can't, but I won't go into that.

In Theravada we would call it restlessness rather than a (zen) sickness. In the articles on zen sickness I've read, the recommendation is lots of sleep, or get drowsy with alcohol, if permitted, and then get to sleep. But if restlessness is, like I say, unbearable sleep is not an option.

The answer is learning how to abide in emptiness after letting go of emptiness. How to do that is another topic.

The deep state of samadhi in which Master Han Shan was in for 5 days is, in the Theravada tradition equivalent to sanna-vedayita nirodha ( ceassation of perception and feeling) in which when one awakes, enlightenment is gain (but there are controversies, some say back to Anagami phala if it wasn't attained), I haven't a clue!

So it's a bit of way to go before you encounter it and when you encounter it just learn to abide in emptiness, then the restlessness will not go away but lessen. But if you practice jhannas the mind will lead you into sanna-vedayita nirodha for 7 days, like Master Han Shan. The you can tell us about it!

  • The article you referenced seems to be a description of a completely different sickness and different prescription (cure) to the one described (for example) here. Why do you say one reference (i.e. the one in your answer) is more credible than another (e.g. the one in this comment)?
    – ChrisW
    Commented Jun 7, 2015 at 21:40
  • This is the right answer but a good further reading on this phenomenon and how it relates to the Path go to page 244 of "How to Measure and Deepen Your Spiritual Realization." It really is just a phenomenon of uncontrollable psychological creativity that if sought after can be maddening but if passed through would mean you have reached a higher stage of overall transformation. In the book, it is described how some masters would get their students drunk to just get them sleeping through the stage otherwise the hyperactivity can cause psychological problems.
    – Ahmed
    Commented Jun 8, 2015 at 3:29
  • @ChrisW - In your link Hakuyu, who cured him, said it was a psychosomatic problem. In wiki of Hakuin it says: "what in modern terms would be a nervous breakdown". So it's an error of attribution, unless we take "nervous breakdown" as another description of zen sickness, which I ruled out.
    – Samadhi
    Commented Jun 8, 2015 at 15:53
  • Robert Persig once said, "Suddenly I realised that the person who had come this far was about to expire. I was terrified, and curious as to what was coming. I felt so sorry for this guy I was leaving behind. It was a separation. This is described in the psychiatric canon as catatonic schizophrenia. It is cited in the Zen Buddhist canon as hard enlightenment." I wondered whether so-called 'hard enlightenment' is a/another form of zen sickness: but this one would be characterized as catatonia not as restlessness, and depersonalization, etc.
    – ChrisW
    Commented Jun 8, 2015 at 16:10
  • @ChrisW - IMHO one can define zen sickness as one specific type that is encountered on the way towards enlightenment or any form of mental imbalances that happened when practicing zen, related or unrelated to enlightenment. I opted for the first definition
    – Samadhi
    Commented Jun 8, 2015 at 20:47

I would be worried. Happened to me and many other intensive meditators. "Meditation sickness" occurs to those meditators embedded in an ideology or worldview that values silence and stilling thought as superior or as more valuable than thinking or acting. This devalues thought, thinking, and acting in the world. And, these value/devalues are what is associated with "meditation sickness".

Celebrated Zen master Guiding Zongmi, warned that excessive focus on meditation and achieving "inner stillness, and non-critical/non-analytical study of the scriptures led to meditation sickness.

Robert H. Sharf, Professor of Buddhist Studies in the Department of East Asian Languages and Cultures, as well as Chair of the Center for Buddhist Studies, at the University of California, Berkeley, wrote of meditation sickness:

"Meditation sickness" excessive focus in meditation on achieving “inner stillness” (ningji), especially when unbalanced by an engagement with the scriptures, leads to a state described as “falling into emptiness” (duokong), which is, in turn, associated with “meditation sickness” (changing). The term meditation sickness was used by various Buddhist masters as a critique of practices they deemed detrimental to the path, notably techniques that emphasized inner stillness—they seem to have been targeting practices that cultivated a sort of non-critical or non-analytical presentness." -- from p476 Is mindfulness Buddhist? (and why it matters), Robert H. Sharf, University of California, Berkeley, Transcultural Psychiatry 2015, Vol. 52(4) 470–484


I think it's basically impossible to know. According to this page, Hakuin, described it as such:

my heart fire began to rise up­ward against the natural course, parching my lungs of their essen­tial fluids. My feet and legs were always ice-cold: they felt as though they were immersed in tubs of snow. There was a constant buzzing in my ears, as if I were walking beside a raging mountain torrent. I became abnormally weak and timid, shrinking and fear­ful in whatever I did. I felt totally drained, physically and mentally exhausted. Strange visions appeared to me during waking and sleeping hours alike. My armpits were always wet with perspira­tion. My eyes watered constantly.

The article includes a footnote explaining some of the context of such claims about "heart fire":

This was a basic notion in Chinese medical lore. Cf. the statement in the encyclopaedic compilation Wu tsa tsu (Five Assorted Offerings, the section on “Man”), by the Ming scholar Hsieh Chao-che: “When a person is engaged in too much intellection, the heart fire burns excessively and mounts upward.”

Torei’s Biography (1710, Age 25) lists twelve morbid symptoms that appeared: firelike burning in the head; loins and legs ice-cold; eyes constantly watering; ringing in the ears; instinctive shrinking from sunlight; irrepressible sadness in darkness or shade; thinking an intolerable burden; recurrent bad dreams sapping his strength; emission of semen during sleep; restlessness and nervousness during waking hours; difficulty digesting food; cold chills unrelieved by heavy clothing.

He lists very specific ailments that are difficult to tie to particular problems connected with meditation practice, and without further accounts from others claiming to have the same thing, how can we know?

Willoughby Britton at Brown University is investigating problems that are arising in people following Mindfulness at the moment, and it's possible that Hakuin's overzealous nature led him to experience what he did (as her research seems to indicate a connection with overly intense practice).

You can read about it here: The Dark Night of the Soul

  • This is always how I understood it. I think most people underestimate how stressful periods of intense practice can be. In addition to all the psychological shit that can arise, there are the visceral, bodily experiences of stress that come along with it. Most of that comes about from not tempering concentration with relaxation. To use some TCM terminology, it's akin to too much fire and not enough water. Very good answer!
    – user698
    Commented Aug 14, 2017 at 13:27
  • @xxxx Thanks. Interestingly I suffered a GREAT deal, much in the same way that people in the Atlantic article I linked to. It took me three years to feel as though my personality had fully rebuilt itself after a depersonalization. I'd still love to know what I did wrong and how I can avoid it happening again in the future (if possible). Let me ask you: How do you temper concentration with relaxation? By just being? Ie. Letting your mind wander? Thanks. Commented Aug 14, 2017 at 14:55
  • 1
    Considering the Vipassana emphasis on this site, I know I'm going to get a lot of flack for this, but you most often see this kind of reaction in mindfulness-based traditions. Really, all this is is insight gone haywire. The Buddha taught a coupling of samatha (or calming) meditation and insight. The two are inseparable. A good way to think about this is that where Vipassana is the sail and the rudder that steer you through the ocean of delusion, samatha is the keel that adds stability to your mind and allows you to safely explore greater depths. So my advice - do some samatha practice!
    – user698
    Commented Aug 14, 2017 at 15:12

Zen Sickness, by Zen Master Hakuin mentions one cause of it was access striving. In Buddhism you should pratice in a balanced manner.

Does anyone know what this was? Has there been a retrospective medical diagnosis of this?

From what I have gathered from Zen Sickness this is fatigue due to excessive striving and beyond what the body can bear.

Also possible that this is linked to insight knowledges.

Are there equivalent stages of the path in other traditions?

Another way these symptoms can have arisen is higher insights: The Progress of Insight - Awareness of Fearfulness to Knowledge of Re-observation

Also some mild forms of restlessness can be due to low level defilements and excessive thinking and pondering about the Dhamma which is mentioned in (Yuga,naddha) Paṭipadā Sutta.

Should I be worried?

Yes if it is excessive striving. No if it insight knowledges.


The are few borderlines between mystical (enlightenment) and psychotic experiences.

Read 'Psychotic and Mystical States of Being: Connections and Distinctions', the scholarly paper by Caroline Brett, PhD, in the journal of Philosophy, Psychiatry, & Psychology.

The paper is available free on this website http://www.yogapsychology.org/art_psychoticandmystical.html. Or, if you have access to journals through your library you can download a PDF of Brett's article.)

Brett argues and provides significant evidence that psychotic and mystical experiences (enlightenment states of mind) are fundamentally indistinguishable. She gives some critical distinctions:

"...the psychotic invests the conceptualization of the experience with great emotional significance, because it serves the purpose of contextualizing and reifying the sense of identity, which is under threat."

Before enlightenment: chop wood, carry water; after enlightenment: chop wood, carry water. (Zen proverb)

  • this was a good read, but some of the statements seem overly precocious, such as "attention is turned inward, away from involvement in practical or worldly matters, so that the process of perception itself is the focus of attention"...
    – blue_ego
    Commented Aug 20, 2022 at 23:14

Hakuin describes it himself in 'Yasenkanna' - the problem seems to have been that his focus was too cerebral, and the remedy given by the sennin was to direct his energy to his lower body.



I'm grateful for this thread. There are many great resources in the links.

The Dark Night of the soul article is particularly resonant. When I teach students meditation, I explain that these practices should come with a warning label, much like on every pack of cigarettes. There are real dangers in entering into this path of serious practice.

I found solace and many helpful tips on not destroying your life after awakening experiences in Daniel Ingram's book: "Mastering the Core Teachings of the Buddha" which he says he wrote so that others don't mess up their lives after these experiences as he did. https://www.mctb.org/

Kenshos happen. And like Hakuin's first one, they can distract from further progress and lead to narcissistic inflation of self-accomplishment and spiritual materialism.

Find a good teacher you can stay in contact with during the post-retreat integration and subsequent return to the rest of your life.

I still get occurrences of "Zen Sickness" after waves of intense wakeful experiences. No big deal. Just keep bringing it all back to chopping wood and carrying water. IMHO, Dilgo Khyentse's instructions on the "Every Day Practice" are perhaps the most cogent, compact pedagogy for the whole path. See this article on my website: The Everyday Practice by Dilgo Khyentse Rinpoche.

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