Most snakes aren't dangerous to people. Only about 15% of snakes worldwide and 20% in the United States can inject poison when they bite. These snakes are called venomous. In North America, these include the rattlesnake, coral snake, water moccasin, also called cottonmouth, and copperhead. Their bites can cause serious injuries and sometimes death.
Most venomous snakes in North America have eyes like slits and are called pit vipers. Their heads are triangle-shaped and they have fangs. One exception is the coral snake, which has a cigar-shaped head and round pupils. Nonvenomous snakes typically have rounded heads, round pupils and no fangs.
If a venomous snake bites you, call 911 or your local emergency number right away, especially if the bitten area changes color, swells or is painful. Many emergency rooms have antivenom drugs, which may help you.
Most snakebites happen on the arms, wrists or hands. Typical symptoms of a nonvenomous snakebite are pain, injury and scratches at the site of the bite.
After a venomous snakebite, there usually is serious pain and tenderness at the site. This can worsen to swelling and bruising at the site and all the way up the arm or leg. Other symptoms are nausea, labored breathing and feelings of weakness, as well as an odd taste in the mouth.
Some snakes, such as coral snakes, have toxins that affect the brain and nerves. This can cause symptoms such as upper eyelid drooping, tingling fingers or toes, difficulty swallowing, and muscle weakness.
Sometimes, a venomous snake can bite without injecting venom. This is called a dry bite.
After you call 911 or your local emergency number, if possible, take these steps while waiting for medical help:
