What can cause tingling in both lower arms and legs? not hands and feet. persistent for 3 weeks. also when sitting or resting. no loss of sensation.

Tricky: Ok, there's two main distributions of nerve problems: outward along an (injured) nerve or inward from the tips of (sick) nerves. Nerve problems in the middle of limbs.. all four....would not be a regular nerve distribution. Muscle weakness from electrolytes (K, Ca, Mag), sick muscles. No, not fitting with standard patterns. Neurologist would be a specialist in this sort of condition.