Kidney stones

Overview

A kidney stone forms when substances in urine become concentrated and crystallize. Stones vary in size, location, and composition. Those differences matter because they influence whether a stone is likely to pass, how symptoms develop, and which treatment options may be considered.

Having pain in the side or blood in the urine does not prove that a stone is present. Other urinary, kidney, abdominal, or pelvic problems can cause similar symptoms.

Possible symptoms

Symptoms may include pain in the side, back, lower abdomen, or groin; blood in the urine; urinary urgency; discomfort when urinating; nausea; or vomiting. Some stones cause no obvious symptoms and are found during imaging for another reason.

Causes and risk factors

Stone formation is influenced by urine chemistry, fluid balance, diet, certain medical conditions, medicines, anatomy, family history, and previous stones. The relevant factors differ by stone type and by person. Avoid presenting a single food or behavior as the universal cause.

When to seek medical care

Prompt assessment is important when symptoms are severe, urine flow may be blocked, infection is possible, pain cannot be controlled, or the person has circumstances that may increase risk. A clinician can advise on urgency after considering the whole situation.

How kidney stones are assessed

Assessment may include a medical history, physical examination, urinalysis, blood tests, and imaging. The clinician may look for infection, kidney function, the stone’s size and location, and whether urine flow is obstructed. A passed or removed stone may be analyzed to help guide prevention.

Treatment options

Treatment depends on symptoms, stone size and location, infection, obstruction, kidney function, pregnancy status, other health conditions, and patient preferences. Options may include observation with follow-up, symptom control, medicine in selected circumstances, shock-wave treatment, ureteroscopy, or other procedures.

Recovery and reducing future risk

Prevention advice should be individualized. It may involve fluid intake, dietary changes, medicine, or monitoring based on stone composition, urine studies, medical history, and kidney function. A person with fluid restrictions or another medical condition should not follow generic intake advice without clinical guidance.

Questions to ask a clinician

• Where is the stone, and how large is it?
• Is urine flow blocked or is infection a concern?
• What are the reasonable options in my situation?
• What symptoms should make me seek urgent care?
• Should the stone or a urine sample be analyzed?
• What follow-up is needed after the stone passes or is treated?