What other clinical history, examination and investigation would be relevant?

History of:

• Vomiting, diarrhea,

• Drug intake (e.g. diuretics, etc.)

• Oliguria, swelling over feet or face

• Dyspnea, cardiac illness

Examination:

• Signs of dehydration (skin turgor, tongue, etc.)

• Anasarca

• Blood pressure (supine and postural)

• Pulse rate

• Systemic examination for cardiac, renal or liver disease

• Neurological examination

Investigation:

• Urinary sodium and creatinine

• Blood glucose

• Renal function

• Thyroid function

• Cortisol

• Plasma and urine osmolality.