I have non-itchy red dots growing and spreading under my skin as i age on my left arm. what is it?

Angiomas: Cherry angiomas are the most common vascular lesions to appear on human skin. They are made up of clusters of dilated capillaries on the surface of the skin, which accounts for the cherry-red or purple color. No one knows exactly what causes them. Cherry angiomas can occur almost anywhere on the skin, but most commonly on the torso. They rarely occur on the hands or feet.