The seven sacraments · Question 5.4
“Who can receive it, when, and may it be received more than once?”

Anointing of the Sick — strength and comfort in the middle of pain
The Church's answer: It is for a member of the faithful who has begun to be in danger through serious illness or the frailty of age — not for a minor complaint. If the same illness grows worse, or if serious illness returns after a recovery, it can be received again. Work out the particulars by listening to the priest and the medical team together.
If they press further: “Can someone receive it after losing consciousness?” — It can be celebrated when there is reasonable ground to judge that the person would have wanted the sacrament while conscious. The more urgent it is, the less you should delay: tell the priest exactly what the situation is.
In one sentence: “The Anointing of the Sick isn't a once-in-a-lifetime deathbed rite — it's a sacrament of healing and comfort you can receive again when serious illness begins or worsens.”