How can you tell if your bladder is full?

How can I tell if I have a kidney/bladder infection?

• Please read before blindly answering and taking off with a solution that's usually always wrong. I pee a lot. Doesn't hurt when I pee though. When it feels like I could fill a Pool, I end up just filling up a shot glass.. not really, but you get it. Of course there are times when I fool myself and say "woah I guess I really had to go this time" but here's the thing, and it's important I fix this, but... This only happens when I'm horizontal... Not sitting, not when I'm standing, walking, running. At first I though, it's because I relax more, but no, even when I do sit-ups during a workout where my back's on the floor I still provoke whatever's in my bladder to want to come out. I've had this problem in the past to a severe point where I would go, but it'd feel like I badly badly badly had to go again, before I even stepped out of the bathroom. After drinking only filtered water for an entire month (except for maybe a splash of milk for cereal) I still find myself having a hard time falling and staying asleep because of this. Is there some kind of test I can get done to see what's wrong down there? It's not like I've ever held it for too long before, I just drank a lot of soda at one point in my life (a longass point come to think of it...) OH!! before I forget... I bought orange juice. After drinking a small glass, I pee'd, for the entire DAY, more than I had in me!! I swear I pee'd more than my body volume, like I had a canister on my back with a hose feeding into my bladder. I got blood tests done and results came in that my sugar levels were normal, all that cholesterol stuff was good and the numbers were very healthy.

• Answer:

  If this was a kidney infection you would have fevers and lower back pains or abd pains. Bladder infections I know make you pee a lot, the other person who commented on this question sounds more like it though, the one kidney working, it'd explain the pee'ing only in one direction. I know with kidney infections you should never hold your bladder because it'd make it worse. I'm sorry I couldn't help a whole lot, but I can give you the tip's in kidney infections, lower back pain's, fevers, cranberry juice will help if it has anything to do with the kidneys.