Hyponatraemia ? cause

1. ? Euvolaemic

1.1. Plasma Osmolality

1.1.1. Reduced

1.1.1.1. Urine Na

1.1.1.1.1. <20 mmol/l

1.1.1.1.2. > 20 mmol/l

1.1.2. Normal

1.1.2.1. Psuedohyponatraemia

1.1.3. Raised

1.1.3.1. Hypertonic Hyponatraemia

2. ? Hypervolaemic

2.1. CCF, Cirrhosis, Nephrotic Syndrome, ARF

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

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