What causes elevated levels of sodium and chloride?

Elevated sodium and chloride levels may be caused by insufficient water intake, kidney-related diseases, endocrine disorders, or other reasons.

1. Insufficient water intake

When water intake is reduced or excessive fluid loss occurs, it can lead to elevated levels of sodium and chloride. Generally, this condition improves after adequate hydration.

2. Kidney-related diseases

When suffering from kidney diseases such as occult glomerulonephritis, chronic nephritis, rapidly progressive glomerulonephritis, chronic interstitial nephritis, urinary tract infections, Henoch-Schönlein purpura nephritis, hypertensive kidney damage, lupus nephritis, etc., blood tests may also show elevated sodium and chloride levels.

3. Endocrine disorders

Endocrine-related conditions—including hypoparathyroidism, hyperthyroidism, growth hormone-secreting pituitary tumors, prolactinomas, hypocalcemia, hypercalcemia, hypokalemia, and hyponatremia—can also result in elevated sodium and chloride levels.

When sodium and chloride levels are elevated, further diagnostic testing is recommended to determine the underlying cause.