3 ms·

4-6 liters per day ... don't you get http://en.wikipedia.org/wiki/Primary_polydipsia http://en.wikipedia.org/wiki/Primary_polydipsia ?

• haldujai 13y ago
  Polydipsia would explain why he drinks that much. He would get https://en.wikipedia.org/wiki/Polyuria https://en.wikipedia.org/wiki/Polyuria as a result from the volume he is drinking.
• mcv 13y ago
  No idea. Though I do get a dry mouth quite easily.