Typical hereditary compression susceptibility neuropathy (HNPP) 1. Genetic aspects HNPP is an autosomal dominant disorder with a high positive family history and equal onset in both sexes. 2. Clinical aspects HNPP tends to develop between the ages of 10 and 30, with equal onset in both sexes. HNPP is characterized by recurrent mononeuropathy or polyneuropathy, mostly recurrent after minor strain, compression or trauma, with symptoms recovering on their own within weeks or months, and a few residual neurological signs. 3. Electrophysiological aspects Electrophysiological changes are far more extensive than clinical. HNPP electrophysiological abnormalities are characterized by diffuse nerve conduction velocity (NCV) slowing, and even in clinically asymptomatic limbs there are NCV abnormalities. It has been proposed that regardless of the presence or absence of clinical symptoms, if a patient has electromyographic findings of: (i) bilateral distal median nerve motor latency (DML) delay with MCV slowing of not less than 40 m/s; (ii) peroneal nerve DML delay, or MCV slowing; and (iii) median nerve palmar to wrist SCV slowing. It can be an important basis for the diagnosis of HNPP; if the DML of median nerve or SCV of wrist is normal bilaterally, the possibility of this disease can be excluded. 4. Pathological aspects HNPP has characteristic pathological changes, mainly manifested as focal myelin sheath thickening, shaped like salami, located next to Langfinger’s node, with intact axons, and increased number of myelin plate layers can be observed by electron microscopy. This typical salami-like structure formation is the most characteristic pathological change of HNPP and is recognized as a pathological feature with diagnostic significance. 5, HNPP diagnostic points ① recurrent single or multiple nerve palsy; ② electrophysiology with diffuse nerve conduction abnormalities; ③ positive family history; ④ peripheral neuropathology with salami-like structure formation. Clinicians should pay attention to differentiate from hereditary neuropathic myasthenia gravis, peroneal muscular dystrophy, and entrapment neuropathy. Local compression or traction should be avoided in such patients to reduce the occurrence of nerve palsy.