Which symptom is a key indicator of a stroke?

Facial drooping, especially when it occurs on one side of the face, is a key symptom of a stroke due to its association with neurological impairment. When a stroke happens, it typically affects one hemisphere of the brain, leading to weakness or loss of control in the muscles on the opposite side of the body. This manifests visually as a drooping smile or asymmetrical appearance when a person is asked to smile or show their teeth.

While a sudden headache can occur with certain types of strokes, particularly hemorrhagic strokes, it is not as definitive or widespread as facial drooping. Difficulty breathing and a persistent cough are not typical hallmark signs of a stroke; these symptoms are more commonly associated with respiratory issues. Thus, facial drooping serves as a clear and observable indicator that can prompt immediate medical evaluation necessary for stroke assessment and treatment.