Which might indicate to a doctor that there is an issue with someone's body chemistry?

sugar in the blood

sugar in the urine

water in the urine

water in the blood

Sugar in urine would be the best choice here, as high levels are often a sign of kidney malfunction, and are most common in diabetics, also called glycosuria.

Water in urine is a non-issue, as water makes up around 95% water.

Water in blood is a non-issue, as plasma is made of 92% water and makes up around 55% of blood.

Sugar in blood is usually a non-issue, as long as it is within 0.007-0.010g/L