A bite from a
poisonous (venomous) snake or lizard requires emergency care. If you have been
bitten by a snake or lizard that you know or think might be poisonous,
call911or other emergency services immediately. Do not wait for symptoms to
If you are not sure what type of snake or lizard bit you,
call the Poison Control Center immediately to help
identify the snake or lizard and find out what to do next. Medicine to
counteract the effects of the poison (antivenom) can save a limb or your
It is important to stay calm.
Poisonous snakes or lizards found in North America include:
Maine, Alaska, and Hawaii are the only states that don't
have at least one poisonous snake species in the wild.
Symptoms of a pit viper snakebite often appear from minutes to hours after a bite. Severe
burning pain at the site usually begins within minutes, and then swelling
starts spreading out from the bite.
Things that affect the
severity of a poisonous snake or lizard bite include the:
- Type and size of the snake or
- Amount of venom injected (if any).
- Potency of
the venom injected.
- Location and depth of the
- Number of bites and where they occurred on the
- Age, size, and
health of the person who was bitten.
If you do not develop symptoms within 8 to 12 hours, it
is possible that no venom was injected; this is called a dry bite. At least
25%, and perhaps up to 50%, of bites are dry. If poison is released in the bite,
about 35% of the bites have mild injections of poison (envenomations), 25% are
moderate, and 10% to 15% are severe.
It is important to remember
that a snake only injects part of its venom with each bite, so it is still
dangerous after the first strike. A bite from a young snake can be serious. And
a dead snake, even one with a severed head, can still bite and release venom by
reflex action for up to 90 minutes after it dies. Even if you do not develop
symptoms within 8 hours, continue to watch for symptoms for 2 weeks or more.