Urea breath test is done in:
Ketoacidosis
H. pylori infection
Kidney disease
Liver disease
The urea breath test is a rapid diagnostic procedure used to identify infections by Helicobacter pylori, a spiral bacterium implicated in gastritis, gastric ulcer, and peptic ulcer disease. 
It is based upon the ability of H. pylori to convert urea to ammonia and carbon dioxide.