Rattlesnakes are the most widely known of the pit
vipers (family Viperidae). They are found throughout the United States and
parts of Canada and account for most poisonous (venomous) snakebites in North
America. They leave one, two, or three puncture marks on the skin, but you
won't always see any marks.
Rattlesnakes can be up to
8 ft (2.5 m) long and
Rattles at the end of the tail. Young snakes may
only have one rattle or "button," which does not make the rattle
Diamond-shaped markings, blotches, or speckles down the
Pitlike depressions behind the nostrils.
triangular head with slit-shaped pupils and fangs.
A single row of
plates or scales on the undersurface of the snake, including the tail.
Symptoms of a rattlesnake bite usually appear from minutes to
hours after a bite and can include:
If you think you have been bitten by a rattlesnake,
call911or other emergency services immediately.
In this article
This information is produced and provided by the National
Institute (NCI). The information in this topic may have changed since it was written. For the most current information, contact the National
Institute via the Internet web site at http://
.gov or call 1-800-4-CANCER.
WebMD Medical Reference from Healthwise
June 06, 2012
This information is not intended to replace the advice of a doctor.
Healthwise disclaims any liability for the decisions you make based on this