If other finger tips are also getting involved then it is generally due to
nerve compression or a
nerve disorder. Depending on which
finger it is, it can be carpel tunnel syndrome, compression of ulnar nerve, compression of radial nerve. Diabetes or hypothyroidism too can be the cause. Very cold climate, peripheral vascular disease, panic disorder, leprosy, alcoholic neuropathy, compression of cervical spinal nerves, are the other causes.