Which one do you write?
hunger pains (wrong)
hunger pangs (right)
"Hunger pangs" and "hunger pains" are two ways of talking about the same thing: that feeling when your stomach tells you it's time to eat. Both phrases are pretty much the same, describing the discomfort in your belly that says, "Hey, I need some food!"
People started saying "hunger pangs" back in the late 1700s. The word "pangs" just means sharp pains or distress, and it caught on as a way to talk about that empty stomach feeling.
Over time, the eggcorn, "hunger pains," developed. Instead of using "pangs," it uses "pains" to express the same idea. "Hunger pangs" is technically the correct term and the more commonly used phrase. But both work, and both versions are widely accepted, so use whichever you prefer. 
Whether it's pangs or pains, both phrases describe those grumbly, gotta-eat-now sensations when your body is telling you it's time for food.