Freshly collected normal urine is ideally clear, possibly slightly cloudy due to the presence of epithelium and mucus.
It also becomes slightly cloudy due to the long standing of the sample, so the collected sample must be delivered to the laboratory as soon as possible so as not to distort the result of the analysis. A small amount of water drunk can also cause cloudy urine in a healthy person.
Severe turbidity of urine is caused by erythrocytes, leukocytes, bacteria, mucus, a significant amount of salts or epithelial cells, etc.