Many things can cause kidney pain. It can be due to health problems such as:

• Bleeding in the kidney, also called a hemorrhage.
• Blood clots in kidney veins, also called renal vein thrombosis.
• Dehydration
• Kidney cysts (fluid-filled pouches that form on or in the kidneys)
• Kidney stones (Hard buildups of minerals and salt that form inside the kidneys.)
• Kidney trauma, which could be caused by an accident, a fall or contact sports.

Some diseases that can cause kidney pain are:

• Hydronephrosis (which is swelling in one or both kidneys)
• Kidney cancer or a kidney tumor
• Kidney infection (also called pyelonephritis)
• Polycystic kidney disease (a genetic illness that causes cysts to form in the kidneys)

You could have one of these health problems and not have kidney pain. For example, most kidney cancers don't cause symptoms until they're advanced.

Call your health care provider right away if you feel constant, dull, one-sided pain in your back or side. Ask for a same-day appointment if you also:

• Have fever, body aches and fatigue.
• Had a recent urinary tract infection.
• Feel pain when you pee.
• See blood in your urine.
• Have an upset stomach or vomiting.

Get emergency care if you have sudden, serious kidney pain, with or without blood in your urine.