Kidney stones (also called renal calculi, nephrolithiasis or urolithiasis) are hard deposits made of minerals and salts that form inside your kidneys.
Diet, excess body weight, some medical conditions, and certain supplements and medications are among the many causes of kidney stones. Kidney stones can affect any part of your urinary tract — from your kidneys to your bladder. Often, stones form when the urine becomes concentrated, allowing minerals to crystallize and stick together.
Passing kidney stones can be quite painful, but the stones usually cause no permanent damage if they are recognized in a timely fashion. Depending on your situation, you may need nothing more than to take pain medication and drink lots of water to pass a kidney stone. In other instances — for example, if stones become lodged in the urinary tract, are associated with a urinary infection or cause complications — surgery may be needed.
A kidney stone usually will not cause symptoms until it moves around within your kidney or passes into your ureters — the tubes connecting the kidneys and the bladder. If it becomes lodged in the ureters, it may block the flow of urine and cause the kidney to swell and the ureter to spasm, which can be very painful. At that point, you may experience these signs and symptoms:
- Severe, sharp pain in the side and back, below the ribs
- Pain that radiates to the lower abdomen and groin
- Pain that comes in waves and fluctuates in intensity
- Pain or burning sensation while urinating
Other signs and symptoms may include:
- Pink, red or brown urine
- Cloudy or foul-smelling urine
- A persistent need to urinate, urinating more often than usual or urinating in small amounts
- Nausea and vomiting
- Fever and chills if an infection is present
Pain caused by a kidney stone may change — for instance, shifting to a different location or increasing in intensity — as the stone moves through your urinary tract.
When to see a doctor
Make an appointment with your doctor if you have any signs and symptoms that worry you.
Seek immediate medical attention if you experience:
- Pain so severe that you can not sit still or find a comfortable position
- Pain accompanied by nausea and vomiting
- Pain accompanied by fever and chills
- Blood in your urine
- Difficulty passing urine
