Very often people deliberately go out of their way to cause pain or problems to others. When they do this, they are inflicting pain on them; they are doing things that they hope will make others experience something unpleasant.
*The General wanted his troops to inflict pain on the prisoners.
When you are afflicted with pain or illness, you suffer; the pain affects you badly, and it causes severe problems. You may suffer either physically or mentally.
*Many countries in Africa are afflicted by civil war.