A blood vessel occlusion system and method includes a handheld probe including a power source, the probe being adapted to transmit energy from the power source through a body surface and into a target blood vessel, for example a varicose vein. Further included is a manual or automatic switch mechanism adapted to enable and disable the power source in response to a predetermined level of compression applied, by means of the probe against the target blood vessel. When the blood vessel is compressed sufficiently to collapse and substantially slow or substantially prevent a flow of blood therethrough, the power source is activated and the vessel is cauterized, leaving the blood vessel in a condition that is resistant to recanalization.