Some common causes of tingling in the left leg include a lower back injury, sitting in the same position too long, pressure on the nerves in the spine, a lack of vitamin B12 and certain medications, notes MedlinePlus. Tingling most often occurs in the legs, hands, feet and arms.
While many of the common causes of tingling in the left leg are relatively minor, tingling can also be a symptom of a more serious condition, notes MedlinePlus. For example, it can be a sign of diabetes, multiple sclerosis or a seizure. Patients should contact their doctor if the tingling in their leg is worse when they walk or they have other unusual symptoms. If they cannot control the leg's movement, patients should call 911, recommends MedlinePlus.