Vitiligo is a disorder that causes your melanocytes to stop producing pigment, which can cause your skin to develop lighter spots. It’s possible to have only one tiny area with depigmentation or larger patches that grow over time. Because vitiligo has much in common with other skin illnesses, your doctor will need to examine you thoroughly to make a diagnosis. They might also order a blood draw or eye test for more definitive answers. Then, once you’ve been diagnosed, you can work with your doctor to create a treatment plan.