What's wrong with this toe? Very thick, yellow. Everything else is normal. Look at the picture.

Hello, there are two reasons for this situation, one is fungal infection, and the other is the lack of trace elements. You can consider further examination and judgment. It is suggested that spironolactone can be taken orally for external use if it is a fungal infection, and it can be supplemented according to the test results if it is a trace element deficiency.