What Are Kidney Stones?
General information on how kidney stones form, their types and symptoms, prevention habits, and situations that require medical attention.
Definition and formation
Kidney stones form when minerals and salts dissolved in urine crystallise and cluster into hard masses. When urine becomes concentrated, typically through low fluid intake, dissolved substances exceed their crystallisation threshold and stone nuclei begin to form.
Protective substances naturally present in urine, such as citrate, inhibit this crystallisation; people with low citrate levels form stones more easily. The mechanism is described in detail on our potassium citrate page.
- Most common type
- Calcium oxalate stones
- Typical symptom
- Severe cramping pain in the flank
- Diagnosis
- Imaging and urine analysis
- Strongest prevention
- Adequate fluid intake
Types of stones
The most common are calcium oxalate stones, accounting for roughly three quarters of all cases. Less frequent are uric acid stones (associated with acidic urine), infection-related struvite stones and hereditary cystine stones. The stone type directly shapes prevention advice, which is why analysing a passed stone is valuable.
Symptoms
Small stones may pass without any symptoms. When a stone moves into the ureter, the typical picture is sudden, severe pain in the flank coming in waves, which may radiate towards the groin. Blood in the urine, nausea, vomiting and burning during urination may accompany it.
Habits that reduce stone formation
The measure with the strongest evidence is drinking enough water to keep the urine light in colour. Reducing salt intake lowers urinary calcium excretion. Moderating animal protein, avoiding excessive oxalate-rich foods and including natural citrate sources such as citrus fruit are common recommendations. For recurrent stone formers, prevention is personalised by the physician according to stone type and urine studies.
When to see a physician
Unbearable pain, pain accompanied by fever and chills, visible blood in the urine, inability to urinate, suspected stones in people with a single kidney and suspected stones in pregnancy require assessment without delay. A stone with fever is an emergency.
This page is intended as general health information; for diagnosis and treatment, please consult your physician.
Frequently asked questions
Do kidney stones pass on their own?
A large proportion of small stones pass spontaneously with plenty of fluids. Size and location are decisive; monitoring and any intervention are decisions for the physician.
What causes kidney stones?
Concentrated urine, an excess of stone-forming substances and a shortage of protective substances such as citrate act together. Low fluid intake, high salt consumption, certain dietary patterns and family history increase the risk.
How does citrate prevent kidney stones?
Citrate binds calcium in urine and makes it harder for crystals to nucleate and grow. The mechanism is described on our potassium citrate page.
Which foods cause stones?
No single food causes stones; the overall pattern matters. Excess salt, excess animal protein and a diet very rich in oxalate can increase risk. Personal dietary plans are built according to the stone type.
Aymed İlaç Sanayi manufactures authorised medicinal products in urology and nephrology. This page does not contain diagnostic or treatment advice; it is intended as general health information.