According to Cedars-Sinai, CIDP occurs when the body’s immune system attacks the myelin sheaths around nerve cells. But exactly what triggers this isn’t clear. Symptoms are usually the same for all types of CIDP. They can include: Tingling in the arms and legs  Gradual weakening of the arms and legs  Loss of reflexes Loss of balance and your ability to walk  Loss of feeling in the arms and legs, which often starts with not being able to feel a pin prick