The reasons for feeling cold in both thighs are lower limb vascular diseases, lower limb arthritis, etc., as follows: 1, lower limb vascular diseases: such as lower limb occlusive vasculitis, mostly due to lower limb artery occlusion caused by lower limb blood supply disorders, sometimes there will be cold extremities, skin whitening, and also cold, painful situation, the specific identification, must be the lower limb vascular ultrasound examination, to observe whether there is insufficient blood supply The arthritis of the lower extremities: arthritis is particularly susceptible to cold, cold, when the cold invasion will lead to a reduction in blood supply around the joints, vascular constriction, in the cold will induce arthritis, such as synovitis, degenerative osteoarthritis, can aggravate the symptoms in the cold, the specific MRI examination and X-ray of the lower extremities to make a clear diagnosis.