Snakebites: First aid

By Mayo Clinic Staff

Most North American snakes aren't poisonous. Some exceptions include the rattlesnake, coral snake, water moccasin and copperhead. Their bites can be life-threatening.

If you are bitten by a poisonous snake, call 911 or your local emergency number immediately, especially if the area changes color, begins to swell or is painful. Many hospitals stock antivenom drugs, which may help you.

If possible, take these steps while waiting for medical help:

  • Remain calm and move beyond the snake's striking distance.
  • Remove jewelry and tight clothing before you start to swell.
  • Position yourself, if possible, so that the bite is at or below the level of your heart.
  • Clean the wound, but don't flush it with water. Cover it with a clean, dry dressing.
  • Don't use a tourniquet or apply ice.
  • Don't cut the wound or attempt to remove the venom.
  • Don't drink caffeine or alcohol, which could speed the rate at which your body absorbs venom.
  • Don't try to capture the snake. Try to remember its color and shape so that you can describe it, which will help in your treatment.

Of the poisonous snakes found in North America, all but the coral snake have slit-like eyes and are known as pit vipers. Their heads are triangular, with a depression (pit) midway between the eye and nostril on either side of the head.

Other characteristics are unique to certain poisonous snakes:

  • Rattlesnakes rattle by shaking the rings at the end of their tails.
  • Water moccasins' mouths have a white, cottony lining.
  • Coral snakes have red, yellow and black rings along the length of their bodies.
April 16, 2015