I have a lot of pimples on my arms,they are harmless ,no itch , but are red and bumpy,normal? how can they go away?

Keratosis pilaris: Keratosis pilaris (KP, also follicular keratosis, lichen pilaris) is a common, autosomal dominant, genetic follicular condition that is manifested by the appearance of rough, slightly red, bumps on the skin. It most often appears on the back and outer sides of the arm. It's harmless.Moisturizing or keratolytic treatments: urea, lactic/ glycolic/salicylic acid creams can help.

Keratosis Pilaris: Thank you for your question. Red bumpy non-itchy pimple like lesions on the arms may be caused by many things. There are forms of inflammatory conditions of the skin that could cause a rash as well as responses to external/internal sources such as allergies or otherwise. Having an examination & evaluation performed by a qualified medical practitioner would be helpful in diagnosis & treatment.