Suggestive of mineralocorticoid deficiency


The sodium is significantly low (results repeated below), and the potassium is high, consistent with sodium loss and potassium retention by the renal tubules in mineralocorticoid deficiency. Under those conditions, water is lost with the sodium, leading to hypovolemia and orthostatic hypotension as is seen in this patient.

In hypovolemia associated with diabetes insipidus or pure dehydration, sodium is elevated because only water (not sodium) is lost in those situations.

TSH is elevated, though not severely so, and is consistent with borderline hypothyroidism. This finding is consistent with the history of fatigue. Hypothyroidism in the setting of a diffusely enlarged thyroid gland is suggestive of early stage chronic (autoimmune) inflammation in the thyroid; this process may be associated with simultaneous autoimmune destruction of other endocrine organs.

The hemoglobin is also low, which may occur in chronic disease and may also contribute to the patient's feeling of tiredness.

                         Patient                Reference
Hemoglobin (B)          9.4 g/dl               11.7 - 15.5
Sodium (S)              126 meq/l                136 - 145
Potassium (S)           5.8 meq/l                3.5 - 5.1
Chloride (S)             98 meq/l                 98 - 107
CO2, total (S)           20 meq/l                  23 - 29
Creatinine (S)          1.8 mg/dl                0.7 - 1.2
Urea nitrogen (S)        52 mg/dl                   7 - 18
BUN/creatinine ratio     29:1                  12:1 - 20:1
Calcium (S)            11.3 mg/dl               8.4 - 10.2
Phosphorus (S)          2.6 mg/dl                2.7 - 4.5
TSH (S)                 9.8 uU/ml                0.4 - 5.5

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