Postural orthostatic tachycardia syndrome is a hetero-geneous condition of dysautonomia and suspected autoimmunity characterised by abnormal increments in heart rate upon assumption of the upright posture accompanied by symptoms of cerebral hypoperfusion and sympathoexcitation. An increase in heart rate equal to or greater than 30 bpm or to levels higher than 120 bpm during a head-up tilt test is the main diagnostic criterion. Manage-ment includes both non-pharmacological and pharma-cological treatment focusing on stress management, volume expansion and heart rate control.