Introverts love closeness, but they also need space. To recharge. To refuel. To think. They have a big heart, but they also drain too damn fast. So if you really care, let them be alone for a while. They may not say it, but trust me, they'll love you even more.
Introverts can't express pain. They're not weak, they just don't want to burden you. They'll just suffer alone in silence instead of asking for help. They've seen so much of it that now it just doesn't matter. They've learned to deal with it. Absorb it. Overcome it. All alone.
People don't understand an introvert's pain. They keep quiet. Don't say much. They don't want to burden anyone. They fight it alone. And suffer in silence.
Introverts don't know how to ask for help. Trust me, even when they're in pain, they won't say a word. That's how they are. They won't burden you. They'll bear the pain alone. They just disappear and come back when they're good.