evidence: Tongue deviation can be useful for detecting stroke, but needs to be considered together with other more common signs of a stroke, according to the BE-FAST acronym (balance, eyes, face, arms, speech). [...] Physicians and scientists who reviewed the information generally agreed that tongue crookedness, or "tongue deviation" in clinical terms, could be useful for detecting a stroke, but cautioned that it should not be used on its own and is best considered together with FAST, especially since the ability to detect a stroke accurately using tongue deviation has not been determined yet. For example, not all cases of stroke display the sign, and a person may also display the sign without actually having a stroke. [...] Tongue deviation might happen after a stroke, but it is not a common sign and if you see it, it is likely to be present along with other, more obvious signs of stroke: such as weakness of the arm or leg on one side, a drooping face on one side, slurred or unintelligible speech. These are part of the FAST (Face, Arm, Speech, Time – get to hospital quickly) message. You would never see tongue deviation as a symptom on its own.