Question

Patient with hyponatremia and dilute urine (urine Osm <100 mOsm/kg):

a) Syndrome of inappropriate antidiuretic hormone secretion (SIADH)
b) Diabetes insipidus
c) Cushing syndrome
d) Hyperaldosteronism

Answer 1

Hyponatremia and dilute urine with urine osmolality less than 100 mOsm/kg can be caused by the syndrome of inappropriate antidiuretic hormone secretion (SIADH). SIADH is a condition where the body produces too much antidiuretic hormone (ADH), causing water retention and dilution of urine. Conditions such as tumors, infections, medications, or lung diseases can lead to excessive ADH production.

Step-by-step explanation:

Hyponatremia and dilute urine with urine osmolality less than 100 mOsm/kg can be caused by the syndrome of inappropriate antidiuretic hormone secretion (SIADH). SIADH is a condition where the body produces too much antidiuretic hormone (ADH), causing water retention and dilution of urine. This leads to low sodium levels in the blood.

In SIADH, the excessive production of ADH can be due to various factors such as tumors, infection, medications, or lung diseases. The increased ADH levels in the blood result in the kidneys reabsorbing too much water, leading to dilute urine and hyponatremia.

Examples of conditions that can cause SIADH include small cell lung cancer, pneumonia, brain tumors, and certain medications. To diagnose SIADH, medical professionals may perform blood tests, urine tests, and imaging studies.