28th August 2020

A patient came to see his general practitioner (GP) a few weeks ago feeling tired and irritable

A patient came to see his general practitioner (GP) a few weeks ago feeling tired and irritable. He was experiencing frequent headaches and the GP felt that his symptoms were likely due to depression but sent off some blood tests to rule out an organic cause. The results are as follows: random plasma glucose 9.1mmol/L, sodium 129mmol/L, potassium 4.2mmol/L, bicarbonate 22mmol/L, creatinine 49mmol/L, urea 5.0mmol/L, plasma osmolality 270mOsmol/kg . 

For the patient above, please select the SINGLE most likely diagnosis. Select ONE option from the list above.

Normal Ranges:
Na⁺: 133–146 mmol/L
K⁺: 3.5–5.3 mmol/L
Urea: 2.5 – 7.8 mmol/L
Creatinine: ♂ 59–104 μmol/L   ♀ 45–84 μmol/ L
HCO₃: 22 – 26 mmol/L
Serum osmolality: 275 – 295 mOsmol/kg
Random plasma glucose: 4.0 to 9.0 mmol/L