The bladder is a muscular sac in the pelvis, just above and behind the pubic bone. When empty, the bladder is about the size and shape of a pear. Urine is made in the kidneys and travels down two tubes called ureters to the bladder. The bladder stores urine, allowing urination to be infrequent and controlled.
However, several different bladder problems can cause pain. Three of the most common causes of bladder pain are interstitial cystitis, urinary tract infection, and bladder cancer.
Interstitial cystitis is a chronic condition in which the bladder becomes inflamed and irritated. The inflammation stiffens the bladder wall and makes it difficult for the bladder to fully expand when filling with urine. People with this condition may also urinate more frequently or feel an urgent need to urinate, yet they may only pass a little bit of urine each time.
Urinary Tract Infection
The urinary tract is normally sterile, but sometimes bacteria can enter through the urethra, which connects the bladder with the outside of the body. A urinary tract infection (UTI) can affect any part of the urinary system, but it is most common in the bladder. Women are also much more likely than men to develop a bladder infection.