Not allowed to give medical advice here, but I would anticipate anxiety and insomnia for a while.. but those can drive a person crazy or drive them back to relapse, so while they don't sound like life-threatening concerns, they are sobriety threatening! We tend to try to quell them in any way we can and may end up turning to other substances, qualifying that it's okay because they are not the thing we are addicted to, but they can steer us right back to drinking.