There is no clear size regulation for very small stones, and different treatments should be carried out according to the size of the stones, which can be treated by general treatment, medication and extracorporeal shock wave lithotripsy. 1. General treatment: patients with very small stones under the right kidney should drink more water and exercise properly, which can promote the discharge of stones. 2. Medication: Small stones less than 0.6cm can be treated by taking medication, such as potassium citrate and sodium bicarbonate to alkalize the urine for uric acid stones. 3. Extracorporeal shock wave lithotripsy: stones larger than 0.6 cm and smaller than 2 cm should be treated with extracorporeal shock wave lithotripsy, which utilizes high-energy shock waves to focus on the stone and then act on it, so that the stone will be cracked and discharged out of the body with the urine. Patients with very small stones in the lower part of the right kidney should go to the hospital in time and choose the appropriate treatment under the guidance of the doctor.