"Whoever, therefore, eats the bread or drinks the cup of the Lord in an unworthy manner will be guilty of profaning the body and blood of the Lord. Let a man examine himself, and so eat of the bread and drink of the cup. For anyone who eats and drinks without discerning the body eats and drinks judgment upon himself."
As Catholics, we fully participate in the celebration of the Eucharist when we receive Holy Communion.
Catholics who have received their First Sacraments, who are not conscious of grave sin are encouraged to devoutly and frequently receive Holy Communion. A person who is conscious of grave sin is not to receive the Body and Blood of the Lord without prior sacramental confession except for a grave reason where there is no opportunity for confession. In this case, the person is to be mindful of the obligation to make an act of perfect contrition, including the intention of confessing as soon as possible (canon 916).
We are also required to fast for just one hour before receiving Holy Communion. Water and medicine do not break a fast. We are obliged to receive this sacrament at least once per year, if possible during Easter.
All who are not receiving Holy Communion are encouraged to express in their hearts a prayerful desire for unity with the Lord Jesus and with one another.