Luke 8:2:

And certain women, which had been healed of evil spirits and infirmities, Mary called Magdalene, out of whom went seven devils,

Notes on Luke 8:2:

Not all sickness is the direct result of demonic activity – these women were healed of evil spirits AND infirmities.

Interestingly, the Bible uses the term “healed of evil spirits” to describe people who are delivered from them.

A person can have more than one demon.  Mary had seven and a certain person at Gadara had a very large number.  They can all be cast out in Jesus’ name.

See also:

Is All Sickness Demonic?
Condition: Demon Possession
Condition: Anything Else Not Listed Here