Quick Facts: Snakebites - Merck Manuals Consumer Version

Q: How do doctors treat a snakebite?

For a nonpoisonous snakebite , doctors will treat it the same way they treat other puncture wounds. They will: Clean the wound Give you medicine to stop infection, if needed Check if you have had a tetanus shot in the last 5 years, and give you one if you haven't For a poisonous snakebite , the doctor will: Usually give you snake antivenom (medicine that works against a specific poison) through an IV (into your vein) Keep you in the hospital for 6 to 8 hours to watch your symptoms, and longer if needed Put you in intensive care in the hospital, if you took in a large amount of venom

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What are the symptoms of a snakebite?

Symptoms of a poisonous pit viper snakebite Symptoms of a coral snakebite

What do I do if I'm bitten by a snake?

How can doctors tell if the snakebite is poisonous?

How do doctors treat a snakebite?

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Adults ages 40 to 60 years, and children ages 5 to 15 years
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Last full review/revision Sep 2019

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Both poisonous and nonpoisonous snakes bite people. Poisonous snakes may inject venom (poison) when they bite. In the United States, people rarely die from snakebites. Some other countries have different poisonous snakes that kill many people.

Only a few types of poisonous snakes live in the United States:

Most common: pit vipers, such as rattlesnakes, copperheads, and cottonmouths
Rare: coral snakes

Most poisonous bites are caused by rattlesnakes. Coral snake bites are very rare.

Nonpoisonous snakebites cause small puncture wounds that are slightly painful. However, if you're scared about being bitten, you may breathe fast, feel sweaty and sick to your stomach, and feel your heart pounding. These symptoms may make you think you have a poisonous snakebite.

Poisonous snakebites cause different symptoms depending on:

The type of snake
The snake's size (bigger snakes carry more venom)
The amount of venom injected (a snake can put different amounts of venom in a bite)
What part of you was bitten
Your age, size, and health

Not all pit viper bites involve venom. If the bite doesn't hurt or swell in the first 30 to 60 minutes, you probably didn't get any venom. If the bite oozes, that can be a sign of venom.

After a venomous bite from a pit viper snake, you'll have:

Redness and swelling, about 30 to 60 minutes after the bite
Bruising and tightness, appearing 3 to 6 hours after the bite
Blisters filled with blood near the bite

You may get a lot of swelling. The swelling usually keeps getting worse for a couple of days.

If you got a lot of venom, you may also have:

Weakness and confusion
Nausea (feeling sick to your stomach) and vomiting (throwing up)
Bleeding gums
Blood in your throw-up, stool (poop), or urine
Breathing trouble, especially if a Mojave rattlesnake bit you

Hours later, you may have

Headache
Blurry vision
Drooping eyelids
Dry mouth
Tingling, numbness, or a metal taste in your mouth, if a rattlesnake bit you

Little or no pain or swelling around the bite
After several hours, the bite may tingle
Muscle weakness, which becomes more severe over time

You may also have:

Blurry vision or double vision
Weakness and confusion
Trouble breathing
Trouble talking or swallowing

If you're bitten by a snake and have symptoms, go to the hospital right away. While you're waiting for medical help:

Move away from the snake
Keep the bitten arm or leg below the level of your heart
Try to stay calm and still
Take off jewelry and tight clothing from the bite area

Things you shouldn't do:

Don’t cut the bite open or suck the bite to try to get the venom out (doesn't work)
Don’t use an ice pack (harmful)
Don't put on a tight band or tourniquet (harmful)
Don't try to catch the snake to bring to the doctor (if the snake is dead, a cellphone picture may help)

If medical care is far away (like when you're out camping) and you don't have any symptoms, clean the bite with soap and water. Watch for signs of infection like you would with any other shallow wound.

To find out if the snakebite is poisonous, your doctor will look at the bite marks. The doctor will ask what the snake looked like. The doctor will also ask about your symptoms.

Is That a Pit Viper?

Pit vipers have certain features that can help distinguish them from nonvenomous snakes: Vertical slitlike pupils Pits between the eyes and nose Retractable fangs Rows of single scales across the underside of the tail Triangular heads (like an arrowhead) Nonvenomous snakes tend to have the following: Rounded heads Round pupils No pits No fangs Rows of double scales across the underside of the tail If people see a snake with no fangs, they should not assume it is nonvenomous because the fangs may be retracted.

Pit vipers have certain features that can help distinguish them from nonvenomous snakes:

Vertical slitlike pupils
Pits between the eyes and nose
Retractable fangs
Rows of single scales across the underside of the tail
Triangular heads (like an arrowhead)

Nonvenomous snakes tend to have the following:

Rounded heads
Round pupils
No pits
No fangs
Rows of double scales across the underside of the tail

If people see a snake with no fangs, they should not assume it is nonvenomous because the fangs may be retracted.

The shape of the bite can sometimes help you know if the snake is poisonous:

Nonpoisonous snakebites usually leave rows of small scratches
Bites from poisonous snakes are usually one or two large punctures (holes)

For a nonpoisonous snakebite, doctors will treat it the same way they treat other puncture wounds. They will:

Clean the wound
Give you medicine to stop infection, if needed
Check if you have had a tetanus shot in the last 5 years, and give you one if you haven't

For a poisonous snakebite, the doctor will:

Usually give you snake antivenom (medicine that works against a specific poison) through an IV (into your vein)
Keep you in the hospital for 6 to 8 hours to watch your symptoms, and longer if needed
Put you in intensive care in the hospital, if you took in a large amount of venom

NOTE: This is the Consumer Version. DOCTORS: Click here for the Professional Version

Click here for the Professional Version

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