On occasions when Catholics are unable to receive the Eucharist, a prayer seeking spiritual communion is customary using one of the following prayers, or something similar.
My Jesus, I believe that you are present in the Most Holy Sacrament. I love you above all things and I desire to receive you in my soul. Since I cannot at this moment receive you sacramentally, come at least spiritually into my heart. I embrace you as if you were already there and unite me wholly to you. Never permit me to be separated from you. Amen.
or My Jesus, I believe you are really present in the Blessed Sacrament. I love you more than anything in the world, and I hunger to receive you. But since I cannot receive Communion at this moment, feed my soul at least spiritually. I unite myself to you now as I do when I actually receive you. Amen.