[Nerve affection in connection with bloodletting II. Four case reports].

Four blood donors with persistent pain and dysfunction of the upper extremity after venepuncture are presented. Physical examinations identified median nerve-affections in all and additionally a varying involvement of other nerves in the elbow region. Such complications appear to have developed following to a vascular lesion. They are rare but potentially disabling and should be known in blood banks and clinical departments to which these patients are referred.