Extreme tiredness, high fever, hypoglycemia or low blood sugar, high blood sugar, kidney
problems causing brain fog, liver
problems causing brain fog, low electrolytes, very high blood pressure, alcohol or drug intoxication, etc can all cause slurred speech. Please do not ignore this and consult a doctor ASAP or maybe go to the ER. MRI of the brain, dental examination, nerve conduction studies, kidney and liver function tests etc will be required.