How Dangerous are Rattlesnakes?


The sun is out and so are the snakes – but just how worried should you be about rattlesnake bites?


North America is home to several species of venomous snakes. Thankfully, none of these are very deadly. The most common venomous snakes are known as pit vipers. These fascinating creatures include rattlesnakes, copperheads, and cottonmouths. They have a unique feature known as heat-sensing pits located between their eyes and nostrils. Coral snakes (elapids) are slightly more poisonous, but bites are so rare they are not a considerable concern. In this blog post, we will explore how to identify pit vipers, discuss the characteristics of specific venomous species, and debunk common myths associated with bites and treatments.


Warning: rattlesnake territory


Inspiration for this topic has come from my not infrequent encounters with snakes in the desert southwest and the incredible fear and fascination my wilderness medical students have around pit vipers. I’m especially keen to enhance education and demystify these snakes.

Identifying Pit Vipers: Pit vipers can be distinguished from non-venomous snakes by the following features.


  • Triangular-shaped heads: Pit vipers have broad, triangular heads, whereas non-venomous snakes typically have narrower, more elongated heads.
  • Vertical pupils: Pit vipers possess vertical, cat-like pupils, while non-venomous snakes generally have round pupils.
  • Heat-sensing pits: Located on either side of the head, between the eye and nostril, these pits allow pit vipers to detect and locate warm-blooded prey.


An example of the smaller profiled head of non-Pit Vipers


Rattlesnakes: Rattlesnakes are well-known pit vipers, characterized by their distinct rattles on the tail. They come in various species and exhibit a range of color patterns.

Copperheads: Copperheads are venomous pit vipers known for their copper-colored heads and hourglass-shaped patterns on their bodies. They are predominantly found in eastern and central regions of North America, often inhabiting forested areas and rocky terrain. They do not possess a rattle.

Cottonmouths (Water Moccasins): Cottonmouths, also known as water moccasins, are semi-aquatic pit vipers predominantly found in southeastern regions of North America. They are known for their dark coloration, wide, triangular heads, and white, cotton-like lining in their mouths.

All pit vipers contain powerful tissue toxins which cause incredible pain and tissue damage. There are some species that may also contain neurotoxins – most notably the Mojave rattler.

Identify Elapids

Coral snake


Coral Snakes: Coral snakes are distinct venomous snakes known for their bright colors, typically displaying bands of red, yellow, and black. They are found primarily in southern parts of the United States and have a secretive nature. Coral snakes possess a potent neurotoxic venom, and although their bites are rare, they should be treated as medical emergencies.


Debunking Myths about Bites 


Myth: Pit Vipers Are Aggressive.

Fact: Pit vipers, like any other snake, prefer to avoid encounters with humans and will typically only bite when they feel threatened or cornered. Their defensive behavior should not be mistaken for aggression. Giving pit vipers space and respecting their natural behavior is essential for safety.


Myth: Smaller Snakes Are More Venomous.

Fact: The size of a snake has no correlation with the potency of its venom. Venom potency varies among individual snakes within a species, and factors such as age, diet, and geographic location can influence venom strength. It’s important to exercise caution around all venomous snakes regardless of their size.


Why do snakes bite?


Bites most often occur when someone is handling the snake. It’s also true that in repeated reviews of bites, men are statistically more likely to get them (75% of bites!).

We also only have less than 10 deaths a year.


Symptoms of a Bite


  1. Localized pain and swelling: Immediately after a pit viper bite, pain, and swelling will likely occur at the site of the bite. Swelling may spread beyond the bite area and can be extensive, depending on the species and individual reaction.
  2. Bleeding and bruising: Pit viper venom contains anticoagulant properties that can lead to bleeding from the bite site or other areas of the body.
  3. Discoloration and tissue damage: Severe envenomation can cause discoloration, blistering, and tissue damage around the bite area.
  4. Systemic symptoms: In more severe cases, pit viper envenomation can lead to systemic symptoms, including nausea, vomiting, dizziness, rapid pulse, low blood pressure, difficulty breathing, muscle weakness, and in extreme cases, cardiac or respiratory failure.

The only Appropriate Treatment:


  1. Seek medical help immediately: Call emergency services or go to the nearest hospital as soon as possible. Time is of the essence in managing snakebites.
  2. Anti-venom is the most important treatment someone can get.
  3. It is worth removing constrictive clothing or jewelry since significant swelling is an anticipated problem.

De-Bunking Myths about Treatment:


Remember, snakebite management should always be conducted by trained medical professionals. Immediate medical attention is crucial to minimize the potential complications associated with pit viper envenomation.


Myth: You need the snake to identify appropriate treatment.

Fact.  All anti-venoms in the US are the same. Do not waste time or put others at risk by gathering the snake


Myth: Suction Devices Work to Remove Venom.

Fact: Suction devices, such as snakebite kits or mouth suction, are not effective in removing venom from snake bites. Numerous studies have shown that these methods are ineffective and can potentially cause more harm. The most appropriate response to a snake bite is to seek immediate medical attention.


Myth: Cutting the wound to suck Venom:

Fact: This causes further tissue damage and delays access to the hospital and effective care.



While sucking and cutting snake bites may sound outlandish to some, this is still a commonly held belief, and suction devices are still being sold at stores like REI. However, the below 3 myths rank as the most surprising beliefs about snake bites I have heard to date:


Sucking the snake’s blood can help with symptoms and treatment

Shooting the wound – and thus blasting away the tissue with venom is a treatment.

If bit, you should kill a deer pull out its beating heart, and apply it to the wound site to suck the venom out.


There is no evidence that any of these treatments work but all present significant risk to the rescuers and delay for the patient.  Please just go to the hospital.


And there you have it some of the truths and myths around rattlesnake bites. Understanding North American pit vipers, their identification, and the characteristics of specific venomous species is crucial for promoting our safety for us and them. If you suspect a bite, please seek medical attention at a hospital or urgent care.



Matthew Valento MD- Washington Poison Center

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