A mnemonic to remember the warning signs of stroke is FAST (facial droop, arm weakness, speech difficulty, and time to call emergency services), as advocated by the Department of Health (United Kingdom) and the Stroke Association, the American Stroke Association, and the National Stroke Association (US). FAST is less reliable in the recognition of posterior circulation stroke. The revised mnemonic BE FAST, which adds balance (sudden trouble keeping balance while walking or standing) and eyesight (new onset of blurry or double vision or sudden, painless loss of sight) to the assessment, has been proposed to address this shortcoming and improve early detection of stroke even further. Other scales for prehospital detection of stroke include the Los Angeles Prehospital Stroke Screen (LAPSS) and the Cincinnati Prehospital Stroke Scale (CPSS), on which the FAST method was based. Use of these scales is recommended by professional guidelines.