Grouping by the blood Na + level (mmol / l) related to clinical symptoms Na+ (mmol / l) Symptoms < 130 (n=5) (%) 130 - < 135 (n=10) (%) 135 (n=85) (%) Total (n=100) p Headache 2 (40) 1 (10) 5 (5.88) 8 <0.05 Nausea, vomiting 4 (80) 5 (50) 11 (12.94) 20 <0.001 Chest pain 0 2 (20) 2 (2.35) 4 Irritation 2 (40) 0 5 (5.88) 7 >0.05 Abdominal pain 1 (20) 0 4 (4.71) 5 >0.05 Tremor 1 (20) 4 (40) 22 (25.88) 27 >0.05 Blood Na + level <130 mmol / l is related highly to clinical symptoms of nausea, vomiting 80%, restlessness 40%, headache 40%.