Why cutting off circulation can backfire
Snake venom does not simply rush from a bite into the bloodstream. Much of it moves through the lymphatic system, a network that carries fluid from tissues back toward the circulation. Muscle movement can help push that fluid along, which is one reason keeping the bitten limb still matters.
A tight tourniquet may slow some venom from leaving the limb, but it does not reliably seal the bite or neutralize the venom. Meanwhile, it restricts blood flow. The tissues beyond the constriction receive less oxygen, and venom remains concentrated around the bite. Some venoms can directly damage tissue, so adding prolonged loss of circulation may make local injury worse.
A tourniquet is not the same as pressure immobilization
Pressure immobilization uses a firm, broad wrap and a splint to limit limb movement while preserving circulation. It is a distinct technique, recommended only in particular settings and for certain snakebites; it is not the same as tying a narrow band tightly around a limb.
The practical distinction is important: trying to trap venom with a tourniquet can injure the limb without stopping the bite’s effects. Suspected snakebite needs urgent medical care, not a tight constriction that may leave the tissue on the far side starved of blood.
