EWTN Catholic Q&A
Holy Eucharist
Question from Anna on 10-15-2012:

Can I receive the Holy Eucharist twice in one day? Thank you. Anna

Answer by Richard Geraghty on 10-28-2012:

Dear Anna,

Not as a usual practice. But there are exceptions. For instance a person could have received Holy Communion at Mass, gotten sick later the same day, and received it again in the last sacraments.

Dr. Geraghty