Pain is a distressing feeling often caused by intense or damaging stimuli, such as stubbing a toe, burning a finger, putting alcohol on a cut, and bumping the "funny bone". Because it is a complex, subjective phenomenon, defining pain has been a challenge. The International Association for the Study of Pain's widely used definition states: "Pain is an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage. Pain motivates the individual to withdraw from damaging situations, to protect a damaged body part while it heals, and to avoid similar experiences in the future. Most pain resolves once the noxious stimulus is removed and the body has healed, but it may persist despite removal of the stimulus and apparent healing of the body. Sometimes pain arises in the absence of any detectable stimulus, damage or disease.

While doing YeokGeun in GiCheon basic static postures, most of beginners may feel uncomfortable, uneasy, and tense at extreme level, most probably arising from hidden/unconscious physiological or emotional or psychological tension/stress or pre-existing/potential injuries or blocked energy channels that have been accumulated or underestimated for many years out of their consciousness. However, it doesn't mean pain is always good for healing oneself. Because pain can not only heal oneself but also destroy itself if it weren't coming along as a healing process. That's why it's very important for a GiCheon teacher to be able to recognize whether students pain comes along for healing or not and, if not, how to cope with it. In terms of healing pain, it's very interesting to notice that what nociceptor is and how it works because the pain brought by YeokGeun training is very much like what nociceptor does stimulates our body in order to healing ourselves.

Specialized peripheral sensory neurons known as nociceptors alert us to potentially damaging stimuli at the skin by detecting extremes in temperature and pressure and injury-related chemicals, and transducing these stimuli into long-ranging electrical signals that are relayed to higher brain centers. The activation of functionally distinct cutaneous nociceptor populations and the processing of information they convey provide a rich diversity of pain qualities. Pain, as a submodality of somatic sensation, has been defined as a “complex constellation of unpleasant sensory, emotional and cognitive experiences provoked by real or perceived tissue damage and manifested by certain autonomic, psychological, and behavioral reactions”. The benefit of these unpleasant sensations, however, is underscored by extreme cases: patients lacking the ability to perceive pain due to hereditary neuropathies often maintain unrealized infections, self mutilate, and have curtailed life spans. Normally, nociception and the perception of pain are evoked only at pressures and temperatures extreme enough to potentially injure tissues and by toxic molecules and inflammatory mediators. These high threshold physical and noxious chemical stimuli are detected by specialized peripheral sensory neurons (nociceptors). This is in contrast to the high sensitivity of visual, auditory, olfactory, taste, and somatosensory organs to their adequate stimuli. Pain is described as having different qualities and temporal features depending on the modality and locality of the stimulus, respectively: first pain is described as lancinating, stabbing, or pricking; second pain is more pervasive and includes burning, throbbing, cramping, and aching and recruits sustained affective components with descriptors such as “sickening”. The intensity of these global reactions underscores the importance of avoiding damaging situations for survival and maintaining homeostasis. As opposed to the relatively more objective nature of other senses, pain is highly individual and subjective and the translation of nociception into pain perception can be curtailed by stress or exacerbated by anticipation.

While students undergoing different type/level of pain, it's more important for a GiCheon teacher to notice and handle it in order for students to achieve health benefits (along with opening energy channels and developing internal power) through YeokGeun training and enough abdominal breath.. Two sides of the same coin: Healing or Killing Pain A GiCheon teacher should be able to acquire in depth experiences in different types of pain and entailed symptoms, and also how to cope with these. To achieve this ability, one also should be able to recognize differences between healing or killing pain. In this sense, the McGill Pain Questionnaire might be a useful resource not only for a GiCheon teacher but also for practitioners to measure level of pain they are experiencing and to see whether it comes for Healing or Killing.

The McGill Pain Questionnaire consists primarily of 3 major classes of word descriptors–sensory, affective and evaluative–that are used by patients to specify subjective pain experience. It also contains an intensity scale and other items to determine the properties of pain experience. The questionnaire was designed to provide quantitative measures of clinical pain that can be treated statistically.

A Companion of the Healing Process Leaking points in the body usually bring beginners or even a few years of experienced practitioners different types of pain symptoms, when continuing YeokGeun training. Practitioners as well as beginners are most likely to experience one or multiple of the following pain symptoms in the process of self-healing and these are generally considered to be a good sign for it; Pulsing (pulsante), Quivering (temblor), Throbbing (palpitante) Pricking (puncion), Boring (aburrido), Stabbing (punalada) Sharp (fuerte) Hot (caliente), Burning (ardiente) Tingling (hormigueo), Itchy (picazon) Dull (abuurido), Sore (llaga), Hurting (dano), Aching (dolor), Heavy (pesado) Tiring (fatigoso), Exhausting (agotador) Sickening (nauseabundo), Suffocating (sofocante) Unbearable (inaguantable) Penetrating (penetrante), Piercing (perforacion) Tight (apretado), Numb (entumecido), Squeezing (exprimir), Tearing (lagrimeo) Cool (fresco), Cold (frio), Freezing (congelacion) Torturing (torturar) ​ Out of the McGuill index, being "swollen (inchado)" is very typical pain symptom in GiCheon YeokGeun training. Below are typical symptoms, indicating blocked acupuncture points and energy channels or less energy flow in the body that beginners/patients may feel when they attempt to do abdominal breath.: Indigestion, Vomiting, Discomfort in the stomach and or intenstines Moving chest first than a lower belly or abdomen when trying to inhale deeper Difficult to move a lower belly out when inhaling Headache, Dizzy, Feeling heat in the face/head Heart beating faster, etc ​ Especially, feeling headache or dizzy or heat in the face are usually bad symptoms of pain which commonly occurs to those with blood pressure problems- although there are always exceptions - so one must relieve itself through more comfortable way of breathing or practice.