# npm doctor > Check the health of the npm environment. > More information: . - Run all default health checks for `npm`: `npm doctor` - Check the connection to the `npm` registry: `npm doctor connection` - Check the versions of Node.js and `npm` in use: `npm doctor versions` - Check for permissions issues with `npm` directories and cache: `npm doctor permissions` - Validate the cached package files and checksums: `npm doctor cache`