The goal of this clinical trial is to evaluate the proportion of ureteral stones ≤4 mm that pass spontaneously within 4 and 8 weeks and assess if pain, blood test (S-creatinine), stone size, stone location and hydronephrosis can predict stone passage. The participants will be asked to fill in a questionare regarding symptoms, give a blood test and undergo a follow-up computed tomography.

All patients with a diagnosis of ureteral stone ≤4 mm at the Emergency Department in Helsingborg will be asked to participate. If they give consent data regarding age, gender, stone size, stone location, hydronephrosis, S-creatinine, treatments and results from the follow up CT is extraced from the medical records.

Inclusion Criteria:

• all patients with acute renal colic where a CT within 24 hours shows an ureteral stone ≤ 4mm and there is no need for acute intervention.

Exclusion Criteria:

• Those who decline to participate, those who are put under guardianship or is less than 18 years old.

All patients with acute renal colic where a CT within 24 hours shows a ureteral stone ≤ 4mm.