There are many white bubbles in the morning urine of a child, what factors or causes are there?

Patient's question:

Main symptoms: Morning urine has a lot of white foam
Onset time: April of this year
Laboratory test results: No protein. Other tests are normal.

Doctor's answer:

Hello, salt-containing urine is common in children during winter. The urine appears like rice water and often contains a large amount of phosphate or urinary acid. It tends to precipitate after standing. If the urine is placed in a bottle and heated, it will become clear immediately. Salt-containing urine is a normal physiological phenomenon. It can be cured without medication, and the key is to drink plenty of plain water.