Go through these in order and stop at the first one that applies. If you are reading this for someone else, answer for them.
Seek emergency medical help for sudden or worsening confusion, severe unsteadiness, abnormal eye movements, double vision, marked drowsiness, collapse, a seizure, or loss of consciousness.
This is especially important if the person has been vomiting, eating very little, losing substantial weight, or drinking heavily.
Stay with them if it is safe to do so, and tell emergency staff about recent food intake, vomiting, surgery, alcohol use, and any supplements or medicines.
Arrange prompt, non-emergency medical review for ongoing poor appetite, repeated vomiting, unexplained weight loss, increasing forgetfulness, or gradual balance problems.
These symptoms have many possible causes, but nutritional deficiency should be considered.
The article also says
Do not assume that confusion in someone who drinks alcohol is simply intoxication.
Alcohol withdrawal, head injury, low blood sugar, infection, and Gayet-Wernicke syndrome can look similar and may occur together.
Someone who is confused or unable to walk safely should not drive.
Every sign above is quoted from the sofidex article on Gayet-wernicke syndrome. If you are not sure, err upward — it is always reasonable to be checked.