How to Inflict Ailments on Sims in The Sims 4
Being able to inflict ailments on sims in The Sims 4 is a fun fairy ability you can purchase!
You can either add an ailment to a sim, or decide to cure that ailment and be nice to them instead.
Plus, this is a requirement for the discordant fairy aspiration from The Sims 4: Enchanted by Nature!
How to Inflict Ailments on Sims in The Sims 4
If you aren’t yet a fairy, you need to become a fairy to do this! Once you’re a fairy you’ll want to gain some perk points that you can spend on fairy abilities. You’ll need to purchase the cure or apply ailment perk for your sim.

Once you have this you can give any sim any of the 8 available ailments at any time. To inflict an ailment on a sim you’ll click on a sim and choose the fairy menu and from there you’ll want to click apply ailment.

When you do this you’ll have a menu appear that lets you choose any of the available ailments. You’ll see their description too, so you can see exactly what you’d be giving the sim.
This same fairy ability allows you to cure ailments as well! You’ll click on the sim and go to the fairy menu and then click cure ailment instead.

This will immediately cure that sim of any ailment they have without needing to take a cure made with the apothecary skill or head to a naturopath for 1500 simoleons.
Now that you know how to inflict ailments on sims in The Sims 4 you can become a discordant fairy by finishing the aspiration. Finishing that aspiration gives your sim the delightfully discordant reward trait that improves your sims balance when they do ill-intentioned fairy magic!