Freud believed anxiety arises from unacceptable impulses approaching consciousness. The ego uses defense mechanisms like repression, rationalization, and projection to avoid anxiety by distorting or hiding threatening thoughts and desires from awareness. Common defense mechanisms include denying problems, sublimating urges into constructive activities, repressing memories, justifying failures, displacing emotions onto safer targets, blaming others through projection, regressing to childish behaviors, overcompensating in opposition to threats, and intellectualizing emotions away.