If i have no diabetes but excessive thirst then what to diagnosis of my body ? i almost can't sleep for dry mouth and excessive thirst.

Should evaluate: Various medications cause dry mouth, which is often perceived as thirst. A rare possibility is diabetes insipidus. In this condition, the kidneys fail to concentrate the urine, creating excessive urination of mostly water. People with this condition need to drink large quantities of water to keep up with losses. Urine and blood testing, usually by a nephrologist, can help make this diagnosis.

Dry mouth.: It could just be dry mouth from mouth breathing . Some medications can cause dry mouth too.