Patients with small fibre neuropathy experience both loss and gain of function in form of e.g. reduced heat perception and ongoing pain respectively. In this talk, the changes of different peripheral unmyelinated nociceptor classes in both directions, hypo-, and hyperfunction in patients with small fibre neuropathy will be described and linked to clinical symptoms and signs. Differently altered discharge properties of unmyelinated nociceptors could contribute to the enigma of simultaneous heat-induced aggravation of pain and heat hypoalgesia. Although clinical similarity might exist between patients those different discharge patterns might make a difference, when it comes to treatment.