The issue of the efficient relief from pain raised an intensive concern of clinicians and researchers in the second half of the last century. Collected knowledge elucidated the essence of pain on the biological, psychological and social level. Different pathophysiological mechanisms of an acute and chronic pain were explained and provided basis for new diagnostic and treatment procedures. A new medical discipline – algesiology – started to study pain in a systematic way and foster interdiscipline collaboration in the treatment of a syndrome of chronic pain when the symptom becomes the disease itself. Ongoing pathophysiological ambiguities and uneasy correlation between the pain complaint and the objective finding cause clinical and assessment difficulties of the issue of chronic pain.

        Key words: pain – biological, psychological and social relations – acute and chronic pain – correlation between pain and painfulness – modern treatment of pain – algesiology