C'mon now. It's not hang-gliding or dropping acid, it's sitting quietly in a room. Not everything in life should be treated as if it's horrendously risky or can't possibly be understood by people exercising common sense.

Nor, in my opinion, do the agglomeration of various meditative practices and teachings, no matter how old and "sacred" they may theoretically be, necessarily have anything all that critical to add to the subjective experience of simply sitting quietly. Just like the practices and teachings that accompany many organized religions, a lot of meditative lingo and theories about meditative "progress" is, IMHO, horseshit peddled by people who have decided to make a living selling said horseshit or have defined themselves by their unquestioning acceptance of said horseshit.

edit: I should add that I can recognize that, as others discuss in this thread, deep meditation over long periods may trigger various psychological issues for some people. However, it's also true that, for example, eating food can be extremely problematic for some people who have serious eating disorders. That doesn't mean that the mere act of eating, which most people manage to do just fine, somehow needs to be guided by some deep tradition, and I don't believe that sitting in meditation needs such guidance in general either. For most people, meditation is a very gentle, mildly restorative practice that aids mood and focus, not some metaphysically shattering cataclysm.

My personal anecdote - I developed a difficult-to-control, anxiety-inducing thought* while dabbling in meditation a couple of years ago. I experienced a week or two worth of extreme anxiety, and had a panic attack. To this day, the obsessive thought is still with me and causes occasional distress. I can't say with certainty that the meditation practice was the cause, but the timing coincides, and I've never experienced anything like this prior to the meditation practice.

* not exactly a thought, but I'm not quite sure what to call it. It's more of an involuntary, difficult-to-control channeling of my focus/perception toward sensations which I perceive as uncomfortable and disturbing.

I'm really curious about this. Say more?

The perception of my own heartbeat is something that I've always been squeamish about, but for most of my life it was never a problem. It made me a bit uncomfortable during high intensity exercise, but it was easy enough to just ignore.

During meditation, I began to perceive my heartbeat more intensely than ever before, and it became a "center of gravity" that my attention would often "fall into". My attention would gravitate toward intense perception of my heartbeat not only while meditating, but also at other times (while trying to fall asleep, while trying to focus on work, while driving), and paired with my pre-existing squeamishness, this became very uncomfortable. I might go through most of my day normally, but as soon as my mind becomes idle for a bit, or if something triggers me to start thinking about my heart, my mind will uncontrollably gravitate toward perceiving my heartbeat, and I'll struggle to ignore my heartbeat and to focus on other things.

My strategy at the time was to attempt to become more comfortable with my heartbeat through continued meditation. I thought that by deliberately focusing on my heart during meditation rather than trying to ignore it, I could "fight the monster face-to-face", kill off the squeamish feeling, and learn to perceive my heartbeat as a benign sensation.

Unfortunately, I developed a delusion that I might gain the ability to consciously control my heartbeat (analogously to how we can consciously control our breathing when we think about it), and that I'd injure or kill myself because I'm not at all qualified to exercise that kind of control. I convinced myself that this is impossible because the heart uses its own pacemaker, unlike the lungs which are controlled by the nervous system. But this didn't kill the delusion - it just transformed it into a more vague anxiety, centered around the notion that I might be inadvertently abusing whatever regulatory connections exist between my heart and my brain. I think this delusion is really just a transformation of the visceral squeamishness that I originally felt when I began perceiving my heartbeat, into a more cerebral form of "squeamishness". I made the decision to stop meditating a couple years ago, but the delusion still lurks in my subconscious and comes back from time to time.

So to summarize, when it first began, the uncontrollable heartbeat perception paired with the squeamishness/delusion caused a lot of agony for about two weeks. I've gotten significantly better at ignoring my heartbeat and not being so troubled by it, but it's a problem that I haven't been able to completely get over.

Maybe taking refuge in the impermanence of that feeling could help? That the squeamishness is just a state of mind and like all things arises from emptiness (sunyata) and returns to it? But yeah, putting away the practice sounds completely reasonable in this case.

In a Thai tradition I practiced a bit from they'd tell you to not focus your attention and awareness on anything above the heart center at the beginning, to really just keep it at the naval, as these sorts of difficulties with the body aren't uncommon.

I absolutely agree that anyone can (and should!) sit quietly in a room and breath. That could probably fall under a category of beginner pranayama or pratyahara. Physical yoga or qi gong practice is also a great thing to undertake as it begins to develop awareness of breath and sensation at this stage.

But I think what a lot of others here are discussing is a meditation practice that has a goal of uncovering deeper layers of consciousness and realizing the nature of mind. Without support that can be quite overwhelming. If it isn't for you, that's wonderful! It definitely was for me.

Meditation sometimes leads to weird or difficult experiences. That's just like any other effortful activity we engage in. There's many who have encountered similar problems before us and their guidance could mean the difference between astagnant practice and reaching what one aspires to.