Hello,
Dehydration is not likely to cause this. Slight yellowness to the whites of the eyes can be a normal variant for people who are highly pigmented, racially black.
Otherwise, it can represent a problem with a function of the
liver. Some people who are otherwise healthy can have a disorder called Gilbert disease, where the liver doesn't do a certain process well enough, particularly when the body is under
stress.
Other liver diseases can cause this too. I recommend that your son have an exam with his doctor who will also likely due a liver function panel
blood test, which can provide information on how the liver is doing and if it is behind the yellowness.
Finally, excessive
beta carotene (what is in carrots) can cause yellowing, but then the skin of the body is typically more orange as well.
Hope I have answered your query. Let me know if I can assist you further.
Take care
Regards,
Dr Bonnie Berger-Durnbaugh, General & Family Physician