Question: I'm unsure of when I should code 276.50 (Volume depletion, unspecified) versus 276.51 (Dehydration). Could you explain the differences between these two codes and offer some advice on when to code which? -- New York Subscriber Answer: Volume depletion is the loss of both water and salts from cell volume. Use the code for volume depletion when your patient is losing salts but there isn't any specific information in the medical record regarding what was lost. For example: Hyponatremia is a form of volume depletion, but it's coded more specifically. Although volume depletion is obviously associated with dehydration, dehydration is not the same as volume depletion because dehydration refers to water loss without salt loss. Volume depletion can exist with or without dehydration. Dehydration can occur as the result of a number of causes including refusal to eat or drink, blood loss, diarrhea, vomiting and being in a hot environment without taking in enough water. Dehydration can be assessed through tenting of the skin as well as dry mucous membranes.