Excessive thirst (polydipsia) and excessive urination (polyuria) are symptoms of underlying diseases rather than diseases themselves. Polydipsia can be caused by conditions like diabetes, hypokalemia, or mental illnesses that result in a change in the body's fluid balance or osmolality. Polyuria is usually accompanied by polydipsia and occurs when an adult urinates over 2.5-3 liters in a 24 hour period, though it can sometimes be normal due to high fluid intake; it is also commonly linked to diabetes. Both polydipsia and polyuria can have simple causes such as consuming too much caffeine, alcohol, or fluids during pregnancy.