This article describes the effects of a bite from a poisonous snake.

The nature of the venom depends on the type of snake that inflicted the bite.

• rattlesnakes
• cottonmouth snakes
• copperheads
• coral snakes

Rattlesnake bites are immediately painful and signs and symptoms such as those listed below usually begin immediately:

• body as a whole
  • swelling
  • pain at site of bite
  • weakness
  • paralysis
  • tingling
  • numbness
  • thirst
  • tiredness
  • shock
• respiratory
  • difficulty breathing
• eyes, ears, nose, and throat
  • blurred vision
  • eye lid drooping
• skin
  • destruction of tissue
  • discoloration of skin
• gastrointestinal
  • nausea, vomiting
• heart and blood vessels
  • bleeding
  • low blood pressure
  • weak pulse
  • rapid pulse

Cottonmouth and copperhead bites are immediately painful and signs and symptoms such as those listed below, usually begin immediately:

• body as a whole
  • swelling
  • pain at site of bite
  • thirst
  • weakness
  • tiredness
  • shock
  • tingling
  • numbness
• respiratory
  • difficulty breathing
• skin
  • discoloration of skin
  • destruction of tissue
• gastrointestinal
  • nausea, vomiting
• heart and blood vessels
  • weak pulse
  • low blood pressure
  • bleeding

Coral snake bites can initially be painless. In fact, major symptoms such as those listed below may not develop for hours. DO NOT make the mistake of thinking you will be fine if the bite area looks good and you are not in a lot of pain. Untreated coral snake bites can be deadly:

• body as a whole
  • pain at site of bite
  • swelling
  • drowsiness
  • weakness
  • slurred speech
  • headache
  • shock
  • paralysis
  • numbness of the affected area
• respiratory
  • breathing difficulty (change in the pattern of breathing)
• eyes, ears, nose, and throat
  • difficulty swallowing
  • blurred vision
  • feeling of swollen tongue and /or throat
  • eye lid drooping
  • excessive salivation (mouth watering)
• skin
  • discoloration of skin
  • destruction of tissue
• gastrointestinal
  • nausea, vomiting
  • stomach or abdominal pain
• heart and blood vessels
  • low blood pressure
  • weak pulse
• nervous system
  • convulsions

If within 40 minutes of an emergency room: Remove any restrictive clothing, rings, and watches. Have the patient rest. Keep the patient warm. Get the patient to the emergency room as soon as possible.

If farther than 40 minutes from an emergency room, see the injuries document on snake bite for information.

Determine the following information:

• the patient's age, weight, and condition
• identification of the snake if possible
• the time bitten
• the location on the body of the bite

A call is probably not necessary unless summoning an emergency vehicle, as the patient should be seen in an emergency room to determine if the bite contains any poison.

Some snake bites are from nonpoisonous snakes, but 20-30% of the bites from poisonous snakes do not actually inject poison into the wound site and can therefore be treated as a puncture wound.

Some or all of the following procedures may be performed:

• Make an evaluation to determine if poison was injected into the wound site
• Give antivenom if necessary
• Give antitetanus shot if needed
• Treat the symptoms

If treatment is obtained soon enough, only a small percentage of those bitten by a poisonous snake die.