If its decapitated, it means your ideas, projects and dreams cannot be achieved or materialized in short term; dreaming of a big head indicates health and abundance; a small head means the start of an illness and impairment in the economy. Dreaming of a head separated from the rest of the body represents a mismatch between the way you think and the way you act. If you have an ailment in the head, its a sign of adversities to come.
Head dream meaning
Read more about dreaming of Head in other dream meanings interpretations.