Sust. FEM. Content of sodium in the blood less than the lower value of the normal range, which is 135-145 millimoles per litre ( mmol/l. ) There are three degrees of hyponatremia: 1 ) mild, of 130 to 135 ( mml/l ) 2 ) median, 120 to 130; 3 ) serious, less than 120. It is multi: ) inappropriate secretion of antidiuretic hormone (41 ADH; also known as arginine vasopressin (AVP ) or argipresina; (b) ) consumption of excess: 41 b1; water; B2 ) Diuretics; B3 ) tobacco: more four cigarettes or two habanos ( «»«pure» ) per day; c ) weaknesses: c1 ) heart; C2 ) Kidney; C3 ) liver; C4 ) adrenal; (d) ) losses via: d1 ) vomiting; D2 ) diarrhea; e ) Hypothyroidism; f ) consumption: f1 ) «Ecstasy»; F2 ) other drugs. (Excerpt from 41 Wikipedia;. The word of Greek origin, consists of the preposition «hypó»: bass, nouns «nátrion»: sodium, and «áima ( the "AI" diphthong is pronounced «e» ) ': blood, as well as the suffix "AI", with meaning of pathological condition. Antonym: hypernatremia.