Some people would argue that every disease is a result of a demonic attack. I would disagree. I would say that disease (which is a form of death) is a result of sin, and specifically, sin having entered the world through the fall. That is not to say that every disease is a result of a person’s sin… but sin as much as it is a separation from God. A separation from God that needs to be bridged through Christ.
In Matthew 10:1 we read, “And when he had called unto [him] his twelve disciples, he gave them power [against] unclean spirits, to cast them out, and to heal all manner of sickness and all manner of disease.” (bold mine)