In case of hypotension, systolic pressure is below 100 mm Hg, while diastolic pressure is below 60 mm Hg. Arterial hypotension can be primary and secondary. Primary, or essential, hypotension has two forms: Ã ) constitutionally-/hereditarily-determined regulation of the vascular tonus and arterial pressure within existing physiological limits (physiological hypotension); b) a chronic disease with typical symptoms: weakness, dizziness, increased fatigability, headaches, drowsiness, slackness, propensity for orthostatic reactions, faints, motion disease, heightened thermo- and barosensitivity (neurocirculatory asthenia). Secondary arterial hypotension can be observed in case of some infectious diseases, bronze disease, a stomach ulcer, myxoedema, anaemias, hypoglycemia, acute and chronic hepatitis, liver cirrhosis, etc. It can also be provoked by some medicinal preparations.