Extreme tiredness, high fever, hypoglycemia or low blood sugar, high blood sugar, kidney
problems causing brain fog, liver
problems causing brain fog, low electrolytes, brain lesions, very high blood pressure, alcohol or drug intoxication, etc can all cause slurred speech with tiredness. Basilar migraine, complicated migraine, Parkinson’s disease, transient ischemic attacks, hyperthyroid states, and seizures should all be investigated for.