Ive Noticed Over The Last Couple Years That The Toe

Ive noticed over the last couple years that the toe on one foot goes numb when surfing in coldish to cold conditions. It is the number 4 digit, so cant really imagine its just lack of circulation or I feel like it would effect other toes as well. When I got out of the water today, looking at the bottom of my foot the toe appeared whitish and did not regain normal feeling until home and warm.
Any thoughts?