sick
痯 centers on the state of being sick or unwell. It is a rare character with a narrow meaning focused on illness.
痯 combines the sickness radical 疒 with 官, which likely provides the sound. The exact historical development is uncertain, but the structure suggests a phono-semantic compound related to illness.
The sickness enclosure 疒 wraps around 官, like an official confined by illness. Picture a bureaucrat stuck in bed, too sick to work.
For カン, imagine a sick person lying in a can: can -> カン, and the sickness keeps them trapped inside.