Diamondback Rattlesnake Venom Effects on Humans

The western and eastern diamondbacks of the U.S. Southwest/Mexico and Southeast, respectively, are the largest rattlesnakes in the world: the eastern may reach nearly eight feet. While they tend to avoid humans and bite only in self-defense, they can deliver a serious--sometimes fatal--quantity of venom.

Venom Composition

• Most U.S. rattlesnakes have primarily proteolytic, hemotoxic venom, which means it damages tissues and destroys red blood cells. Enzymatic proteins in the venom sabotage clotting mechanisms; enzymes called hemorrhagins promote uncontrolled bleeding. For the snake, the venom has digestive as well as toxic properties.

Other Effects

• While the major effects in humans of diamondback venom involve blood and blood vessels, it may also induce neurotoxic effects, which impair the nervous system.

External Symptoms

• Along with severe pain, rattlesnake bites often induce blistering, nausea, headaches, tingling of the head and extremities, skin discoloration and swelling. Blood may appear at the gums, lips, and nails and in urine and stool.

Long-term Consequences

• Bite victims may suffer prolonged, even lifelong effects. A woman severely bitten by an eastern diamondback still experienced pain, memory loss and other issues for six years afterward.

Mortality Rate

• Antivenin is an effective treatment for diamondback bites. However, if medical aid is delayed, death is possible: While their venom is not as potent as that of some smaller species, diamondbacks' size and their long fangs mean they can inject large quantities. Western diamondbacks may kill more people in the U.S. than any other snake, and the mortality rate from eastern diamondback bites may be as high as 40 percent.