Not really possible to explain without some context.
Urea and Electrolytes are principally regulated by the kidney and can vary depending many factors including hydration, age, medications, and a whole host of acute and chronic medical conditions.
The most you can say from what you've posted is that something appears to be affecting urea and electrolytes (most likely kidney function) and it probably needs further investigation unless this is a longstanding / established pattern in this person.