You always want to be gentle and never force the qi to flow where it’s not ready, because it’ll burn you. You patiently clear blocks and build the meridians to handle greater flows over time.
I often use the gym analogy - you’ll get injured if you push too hard too fast, but do it daily and “grease the groove” and you get strong quickly.
It can cause you damage to you qi body, and set you back in your development. The qi body damage can also have knock on effects and damage the other bodies - mental, emotional and physical. Similar to kundalini raising gone wrong.
If you have illness, or any issues during practice, it’s a good idea to stop and return to a foundational practice called Guarding the Center - simply bring your mind back to lower dan tian, and in life, dial back the incoming bad energy in your environment and what comes into you via your 5 senses. Then you can rebalance your qi and it will not cause damage.
As E.A. Koetting says: “protect your energy”. This includes not allowing disturbing ideas and visions that do not server you into your heart and mind. It’s part of having “good spiritual hygiene” and not attracting parasites too.
If you continue to raise qi wile it’s imbalanced, probably by driving too much impure yang qi up the Du meridian (up your back), it can cause these issues. You want water and fire (the lesser forms of yin and yang) to be balanced in equal amounts so they blend well to build your qi body… this is paralleled in Kabbalah and Hermeticism (alchemy) as the marriage of opposites.
Symptoms of this imbalanced qi happen on a scale, staring with emotional disregulation,
Benebell Wen who teaches Taoist practice translates from the I Ching - The Book of Changes - (I have her course and there’s a lot free on her website and youtube), like so:
“For those with weaker constitutions or dull endowments, start with the preliminary method
of “Guarding the Center.” It is used to warm the inner states and is the most basic of practices
for even the layperson and the inexperienced.”
…
“The Guarding the Center meditation is a method for concentrating the purity of Shen [spirit] in the Qi cavity [lower dan tian], to ground and center that Qi, so that the Three Treasures* are in harmony in each of their respective realms, and to converge the Wu Xing (five elemental changes) into its primordial singularity.Balancing of the five physical senses and five innate spirits, exhibited through balanced temperance and moderation of one’s desires, within the lower dantian (“Ancestral Aperture”) is an essential prerequisite, so that purified Yang can rise naturally during the Lesser Mandala of Heaven practice”
…
“Do not hastily set the River Chariot (Lesser Mandala of Heaven) [microcosmic orbit] into motion, because if you attempt to circulate the River Chariot when the Jing essence of the blood, bones, joints, and marrow are not yet refined, and you force the driving of the River Chariot, you will scorch and deplete the body’s Jing essence, and this harm to the physical body is of no small matter.Thus, calm the center and such stagnation may be avoided.”
*The 3 treasures are Jing (physical robust health), Qi, and Shen (spirit). If your health is great you don’t need to do this practice.
So you get a vicious circle - desires, delusions, and fantasies create unstable, unrefined, impure Yang Qi, which can make you want to get forceful with the qi practices, and then driving the impure yang causes more delusions, which get harder and harder to control, and more and more problems, up to insanity, physical illness, and so my teachers told me - even death by heart attack or stroke.
“Side effects of forcing unrefined Yang up the Du meridian include hindered sight, distracting ringing in the ears, agitation of the heart, and tumultuous intentions.”
