What would cause a lack of thirst? im finding myself not being able to finish even a small bottle of any liquid.

Many foods: Contain water, in winter time people sweat less, your body will tell you when you need it. Now if lightheaded have evaluation.

Sometimes: If you are constipated and backed up you can lose both your appetite and your thirst. Of you are bloated, have round or hard stools, pass a lot of gas or belch a lot, even if you go daily you could be constipated . Force yourself to drink enough water until your urine is almost clear.