Hello and welcome to HCM.
Thank you for your query.
A high
creatinine level is usually seen in
kidney disorders which impair the normal function of the kidneys. But, in your case, as your doctor has ruled out all other causes of a high creatinine level, it could very likely be due to
dehydration. But, high creatinine levels can also result due to intake of a few medications, as no drug history has been mentioned by you, I am assuming your wife is not on any medications, but if she is, then please run them through your treating doctor.
An elevated creatinine level is also seen in chronic conditions like
diabetes mellitus, blood pressure, etc; but these can affect the creatinine level only if they are present for a long duration of time.
Diet should also be ruled out to be a cause as meat and a few citrus containing products can also cause an elevated creatinine. Kindly discuss a suitable diet with a nutritionist. This will also help in lowering the creatinine levels.
I hope I have succeeded in providing the information you were looking for. Please feel free to write back to me for any further clarifications. I would gladly help you.
Best wishes.