UTI (urinary tract infection) is an infection of any part of the urinary system like the kidneys, bladder or urethra. UTI’s usually occur in the bladder or urethra, but more serious infections involve the kidneys. Bladder infections may cause pelvic pain, pain with urination, increased urge to urinate, and blood in urine. Kidney infections may cause back pain, nausea, vomiting and fever. Symptoms may vary from person to person and consult a doctor immediately.