Alcohol can worsen anxiety because of its effects on the body and the brain. In the brain, alcohol changes the levels of serotonin and other neurotransmitters resulting in feeling more anxiety. 

Alcohol-induced anxiety can last for a few hours or up to an entire day after consuming alcohol. While alcohol acts as a sedative so people can put a hold on their anxiety, the sense of relaxation is short-lived. 

When these effects wear off, those pleasant feelings fade quickly which reduces our serotonin levels, which is commonly associated with increased anxiety.