FRACTIONAL EXCRETION OF SODIUM; FENA

What this test checks

Compares sodium in blood and urine to determine whether sudden kidney failure is from dehydration, blockage, or kidney damage.

Why do people get this test?

Specialised test usually ordered in hospitalised patients with acute kidney problems.

When you should consider this test

• Hospitalised with acute kidney failure
• Doctor needs to identify cause of kidney trouble
• Nephrologist (kidney specialist) ordered

How to prepare

Requires both blood and urine samples.