What are snake bites?

Snakes bite either to capture prey or for self-defense. But since there are so many different types of snakes — including both venomous and non-venomous — not every snake bite is created equal.

Different species carry different types of venom. The major categories include:

  • Cytotoxins: Cause swelling and tissue damage wherever you’ve been bitten.
  • Haemorrhagins: Disrupt the blood vessels.
  • Anti-clotting agents: Prevent the blood from clotting.
  • Neurotoxins: Cause paralysis or other damage to the nervous system.
  • Myotoxins: Break down muscles.

Are snake bites dangerous?

The answer might seem obvious, but there are two different types of snake bites. And one is more serious than the other:

  • Dry bites: These occur when a snake doesn’t release any venom with its bite. As you’d expect, these are mostly seen with non-venomous snakes.
  • Venomous bites: These are much more dangerous. They occur when a snake transmits venom during a bite.

Poisonous snakes voluntarily emit venom when they bite. They can control the amount of venom they discharge, and 50 to 70% of venomous snake bites result in envenoming or poisoning. Even with a less serious type of bite, every snake bite should be treated as a medical emergency — unless you’re absolutely sure that the bite came from a non-venomous snake. Any delay in treatment following a venomous snake bite could result in serious injury or, in the worst-case scenario, death.

How common are snake bites?

Snake bites aren’t terribly common in the U.S. — and they aren’t usually fatal. But according to the World Health Organization, between 4.5 and 5.4 million snake bites occur each year and 1.8 to 2.7 million of those cause illnesses. It’s estimated that at least 81,000 to 138,000 people die each year from snake bites.

Even so it is best to treat all snake bites as a medical emergency unless one is certain the bite came from a non-venomous snake. Any delay in treatment following the bite of a venomous snake could result in death or serious injury.

Who is most at risk of suffering a snake bite?

Up to 95% of snake bites occur in either tropical or developing countries. Those who live in South Asia, Southeast Asia and sub-Saharan Africa are particularly affected by venomous snake bites, as they often don’t have access to adequate healthcare services or antivenoms. Snake bites are also especially common in poor communities, often in rural areas. People with specific jobs are also more at risk, including:

  • Agricultural workers.
  • Herders.
  • Fishermen.
  • Hunters.

In North America, most snakes are not venomous. But those that are venomous include the rattlesnake, water moccasin, coral snake and copperhead snake.

What are the symptoms of a snake bite?

If you’re bitten by a snake, your symptoms will differ depending on which type of bite it is. If you suffer a dry snake bite, you’ll likely just have swelling and redness around the area of the bite. But if you’re bitten by a venomous snake, you’ll have more widespread symptoms, which commonly include:

  • Bite marks on your skin. These can be puncture wounds or smaller, less recognizable marks.
  • Sharp, throbbing, burning pain around the bite that you may not feel for a little while after the bite. You may also feel pain all the way up whichever limb was affected, such as in the groin for a bite on the leg or the armpit for a bite on the arm. But not everyone feels pain. For example, a bite from a coral snake can be almost painless at first, but still deadly.
  • Redness, swelling and tissue damage, or complete destruction, in the area of the bite.
  • Abnormal blood clotting and bleeding. Severe bleeding can lead to a hemorrhage or kidney failure.
  • Low blood pressure, a faster heart rate and a weaker pulse.
  • Nausea and vomiting, diarrhea, anxiety, headaches, dizziness and blurred vision.
  • Difficulty breathing, or in serious cases, complete loss of breath.
  • Increased production of saliva and sweat.
  • Weakness in your muscles and numbness in the face or limbs.

If you have an allergic reaction to a snake bite, you could suffer from anaphylactic shock. Many of the symptoms are the same or very similar to the ones listed above, but more severe. But there are a few additional symptoms, including:

  • Difficulty speaking due to extreme tightness in the throat and a swollen tongue.
  • Young children may become very pale.
  • Constant cough and/or wheezing.

Which snakes are venomous?

There are two major groups of venomous snakes:

  1. Elapids (cobra family): There are about 300 venomous species of Elapidae, including kraits, mambas, coral snakes and sea snakes. They have short fangs in the front of the upper jaw and strike downward, followed by chewing. Their venom is mainly neurotoxic but it can also harm body tissue or blood cells. If a cobra bites you, you can die from paralysis of the heart and lungs very quickly after the bite.
  2. Vipers: There are more than 200 species of Viperidae, which includes pit vipers (like rattlesnakes, copperheads, water moccasins, or cottonmouths) and Old-World vipers (adders). They have long, hollow, venomous fangs attached to movable bones in their upper jaw. They fold their fangs back into their mouth when they’re not in use.

Last reviewed by a Cleveland Clinic medical professional on 06/02/2020.


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