Even having red blood cells that you can't see called microscopic hematuria.
即使有你看不见的红细胞也叫微观血尿。
Osmosis-泌尿
Diagnosis involves a history and physical exam, as well as imaging studies like X-rays, CT scans or ultrasound, and finally urinalysis because it might show microscopic or gross hematuria or blood in the urine.
Microscopic hematuria is a medical condition in which urine contains small amounts of blood. Blood quantity is too low to change the color of the urine (otherwise, it is known as gross hematuria). While not dangerous in itself, it maybe a symptom of kidney disease, such as IgA nephropathy, which should be monitored by a doctor.