Chronic cystitis is well and there is still occult blood in the urine, which may be caused by stones or kidney tumors, and the cause of occult blood in the urine is not chronic cystitis. Urine occult blood refers to the presence of hemoglobin in the urine found through chemical testing methods, but due to the low content of hemoglobin, the naked eye may not see the presence of hematuria. In general, there are many causes of urinary occult blood, and patients with chronic cystitis will experience urinary occult blood due to the constant stimulation of inflammation. However, if the patient’s chronic cystitis has been cured and still has occult blood in the urine, it is necessary to consider that it may be caused by other causes, such as stones, kidney tumors and so on. If the patient has bladder stones or kidney stones, the stones may cause bleeding of the mucous membranes, resulting in occult blood in the urine. Patients with kidney tumors may also have occult blood in urine due to tumor compression or irritation. In this case, the patient needs to go to the hospital in time, improve the relevant examination, identify the cause of the disease, targeted treatment.