Sangre de Cristo is Spanish for "the blood of Christ". While modern medicine is truly miraculous in bringing physical health to people and is a powerful tool given by God to mitigate suffering as He remains continually present with us in the good and bad times, medicine does not fulfill wholeness. Wholeness is completed as our physical/medical beings enter into spiritual relationship with this same God who is ever present. This "good news" of God's offering to us a life of complete wholeness is called "the gospel".
In the Bible (for example in Matthew 11:1-6), Jesus self describes His ministry as bringing both physical and spiritual healing (wholeness) to people. Entering into spiritual relationship with God begins and ends by entering into relationship with His Son, Jesus Christ. John 3:16 describes the how of entering this relationship; believe in Jesus Christ and find forgiveness, eternal life, hope and wholeness.