Final answer:
The complication that may occur when a brain tumor compresses the pituitary gland, causing syndrome of inappropriate antidiuretic hormone (SIADH) or diabetes insipidus (DI), is hyponatremia.
Step-by-step explanation:
The complication that may occur when a brain tumor compresses the pituitary gland, causing syndrome of inappropriate antidiuretic hormone (SIADH) or diabetes insipidus (DI), is hyponatremia.
When the pituitary gland is compressed, it can disrupt the normal release of antidiuretic hormone (ADH), resulting in either too much or too little ADH. In the case of SIADH, there is excessive release of ADH, leading to water retention and dilution of sodium in the blood, causing hyponatremia. On the other hand, if there is underproduction of ADH, as in DI, the kidneys are unable to retain water, leading to increased urine production and dehydration.