How Is Fluid Overload Diagnosed? Your doctor will do a physical exam and talk to you about your symptoms and your medical history. Your doctor may be able to diagnose you with fluid overload based on edema and weight gain. You may also need additional lab or imaging tests to determine the underlying cause.

What lab test indicates fluid volume excess?

Serum Osmolality Tests are used as a measurement to determine the number of solutes present in the blood (serum). These tests are typically ordered to evaluate hyponatremia, which is generally a result of sodium lost in the excretion of urine or excess fluid in the bloodstream.

How do you assess fluid balance?

Capillary refill time (CRT) is a good measure of the fluid present in the intravascular fluid volume (Large, 2005). It is measured by holding the patient’s hand at heart level and pressing on the pad of their middle finger for five seconds.