You’re going about your day, maybe getting dressed or glancing at your arms in the sunlight, and you notice them: small, white spots scattered across your skin. They’re not raised. They don’t itch. They’re just… there. Pale little patches that stand out against your normal skin tone.

If you’ve noticed these spots, you’re not alone. They’re surprisingly common, especially as we age. But what are they? Are they harmless? And is there anything you can do about them?

Let’s explore the most likely causes—and when you might want to mention them to a doctor.