Hyponatraemia ? cause

1. S.Na 125, U.Na 40, Hypovolaemic

2. ? Euvolaemic

2.1. Plasma Osmolality

2.1.1. Reduced

2.1.1.1. Urine Na

2.1.1.1.1. <20 mmol/l

2.1.1.1.2. > 20 mmol/l

2.1.2. Normal

2.1.2.1. Psuedohyponatraemia

2.1.3. Raised

2.1.3.1. Hypertonic Hyponatraemia

3. ? Hypervolaemic

3.1. CCF, Cirrhosis, Nephrotic Syndrome, ARF

4. ? Hypovolaemic

4.1. Urine Na

4.1.1. <20 mmol/l

4.1.1.1. Diarrhoea, Skin loss, Vomiting

4.1.2. >20 mmol/l

4.1.2.1. Addisons Disease, Diuretics, Salt losing nephropathy