Location of original<unk>  and<unk>  The location of the reference point for each individual that experiences<unk>  is well conserved and specific to each person, in that a certain location will elicit the phenomenon repeatedly for a given person while<unk> es elsewhere may not. However, frequent and repetitive stimulation of the same original<unk>  location can weaken the phenomenon, making the<unk>  increasingly more discrete with each repeated trial. There is also no evidence of a relationship between the site of the original stimulus and that of the<unk> . Though the location of the<unk>  may remain fairly constant and precise for a particular stimulus location on a single individual, there is no substantial evidence linking any two locations in a definite origin/referred location relationship. Thus, referral patterns are extremely variable and offer little to no indication of where a<unk>  will occur if the location of the original<unk>  is known. The phenomenon is unidirectional. Consequently, scratching an<unk>  in a location that has previously served as the point of a<unk>  does not induce an<unk>  in the person’s typical origination site. Synesthesia and mitempfindung Mitempfindung has been thought to be related to synesthesia in some individuals, specifically digit-color synesthesia. Digit-color synesthesia is a phenomenon in which affected individuals associate individual numbers with certain colors; individuals have been said to "count in colors." Both synesthesia and mitempfindung develop in early childhood and are highly variable among individuals. Furthermore, synesthesia and mitempfindung are both unidirectional. A scratch on the trigger zone creates a referred sensation in a distant body part but not vice versa. Likewise, in synesthesia, a person's association of a number with a color does not mean that that color aways evokes that number for them. Normal and pathological<unk> <unk>  is the class of referred sensation that focuses on the situation in which an<unk>  in one place on the body simultaneously triggers an<unk>  in a different location. Other examples of referred sensation include sensations of temperature, pain, and pressure.<unk>  is commonly observed in completely healthy individuals and can often go unnoticed depending upon the particular person’s self-awareness of their<unk> es and the causes of those<unk> es. The ephemeral nature of<unk>  and its restriction to a very small area on one’s body (the<unk>  is precisely located, it does not induce widespread<unk> ing) make it difficult to document or even notice. The majority of the cases of<unk>  studied by experimenters occur in healthy individuals. Furthermore,<unk>  itself does not confer any adverse effects on the health of those experiencing it. With the exception of the annoyance of feeling multiple<unk> es and a potentially minuscule feeling of pain, it is an innocuous condition. The cause of<unk>  in healthy individuals is still not known for certain, but there are a multiple recorded cases of<unk>  being triggered by certain pathological stimuli. Two men developed temporary referred sensation after suffering from shingles. Here, the referred sensation occurred in the areas previously affected by the shingles. Another man who suffered from hyperpathia and reduced nerve functioning later experienced<unk>  in conjunction with his pathology. This evidence suggests that although<unk>  occurs spontaneously in healthy individuals, certain pathologies make it possible to acquire the condition, even if only temporarily.
Referred itch
Pain out of proportion
Baricity
Referred pain
Coolie itch
Body odor
Ground itch
Grain itch