What sort of problem is a bladder infection without symptoms?

Bacteruria. Bladder infection without symptoms usually referred to as bacteruria is usually benign, however can be due to certain organisms such as pseudomonnas, which don't always cause symptoms. Can be serious if subject has bladder reflux, in which case bactweria can reach and invade the kidney, sometimes without symptoms. Patients with neurogenic bladder dysfunction may not feel anything + have stones etc.
Bacteriuria. It means bacteria present in urine but not causing symptoms of urinary tract infection like dysuria, increase frequency of urination, fever, backache, abdominal pain etc.