Our Health Library information does not replace the advice of a doctor. Please be advised that this information is made available to assist our patients to learn more about their health. Our providers may not see and/or treat all topics found herein.
Snake and Lizard Bites
Poisonous snake or lizard bite
A bite from a poisonous (venomous) snake or lizard requires emergency care. If you have been bitten by a snake or lizard that you know or think might be poisonous, call 911 or other emergency services immediately. Do not wait for symptoms to develop.
If you are not sure what type of snake or lizard bit you, call the Poison Control Center immediately to help identify the snake or lizard and find out what to do next. Medicine to counteract the effects of the poison (antivenom) can save a limb or your life.
It is important to stay calm.
Poisonous snakes or lizards found in North America include:
- Pit vipers (family Viperidae), such as the rattlesnake, copperhead, and water moccasin (also called cottonmouth).
- Coral snake (family Elapidae).
- Gila monster and Mexican beaded lizard.
Maine, Alaska, and Hawaii are the only states that don't have at least one poisonous snake species in the wild.
Symptoms of a pit viper snakebite often appear from minutes to hours after a bite. Severe burning pain at the site usually begins within minutes, and then swelling starts spreading out from the bite.
Things that affect the severity of a poisonous snake or lizard bite include the:
- Type and size of the snake or lizard.
- Amount of venom injected (if any).
- Potency of the venom injected.
- Location and depth of the bite.
- Number of bites and where they occurred on the body.
- Age, size, and health of the person who was bitten.
If you do not develop symptoms within 8 to 12 hours, it is possible that no venom was injected; this is called a dry bite. At least 25%, and perhaps up to 50%, of bites are dry. If poison is released in the bite, about 35% of the bites have mild injections of poison (envenomations), 25% are moderate, and 10% to 15% are severe.
It is important to remember that a snake only injects part of its venom with each bite, so it is still dangerous after the first strike. A bite from a young snake can be serious. And a dead snake, even one with a severed head, can still bite and release venom by reflex action for up to 90 minutes after it dies. Even if you do not develop symptoms within 8 hours, continue to watch for symptoms for 2 weeks or more.
Nonpoisonous snake or lizard bite
Most snakes and lizards in North America are not poisonous. Bites may be frightening, but most do not cause serious health problems. A bite from a small nonpoisonous snake might leave teeth marks, a minor scrape, or a puncture wound without other symptoms. Home treatment often relieves symptoms and helps prevent infection.
Although most nonpoisonous snakebites can be treated at home, a bite from a large nonpoisonous snake (such as a boa constrictor, python, or anaconda) can be more serious. In North America, these snakes are found in the Florida Everglades and zoos, but they may also be kept as exotic pets. The force of the bite can injure the skin, muscles, joints, or bones. Other problems can occur with a nonpoisonous snake or lizard bite even if the reptile is small. A snake or lizard's tooth may break off in a wound or a skin infection may develop at the site of the bite.
Check your symptoms to decide if and when you should see a doctor.
Check Your Symptoms
The medical assessment of symptoms is based on the body parts you have.
- If you are transgender or nonbinary, choose the sex that matches the body parts (such as ovaries, testes, prostate, breasts, penis, or vagina) you now have in the area where you are having symptoms.
- If your symptoms aren’t related to those organs, you can choose the gender you identify with.
- If you have some organs of both sexes, you may need to go through this triage tool twice (once as "male" and once as "female"). This will make sure that the tool asks the right questions for you.
Many things can affect how your body responds to a symptom and what kind of care you may need. These include:
- Your age. Babies and older adults tend to get sicker quicker.
- Your overall health. If you have a condition such as diabetes, HIV, cancer, or heart disease, you may need to pay closer attention to certain symptoms and seek care sooner.
- Medicines you take. Certain medicines, such as blood thinners (anticoagulants), medicines that suppress the immune system like steroids or chemotherapy, herbal remedies, or supplements can cause symptoms or make them worse.
- Recent health events, such as surgery or injury. These kinds of events can cause symptoms afterwards or make them more serious.
- Your health habits and lifestyle, such as eating and exercise habits, smoking, alcohol or drug use, sexual history, and travel.
Try Home Treatment
You have answered all the questions. Based on your answers, you may be able to take care of this problem at home.
- Try home treatment to relieve the symptoms.
- Call your doctor if symptoms get worse or you have any concerns (for example, if symptoms are not getting better as you would expect). You may need care sooner.
Pain in adults and older children
- Severe pain (8 to 10): The pain is so bad that you can't stand it for more than a few hours, can't sleep, and can't do anything else except focus on the pain.
- Moderate pain (5 to 7): The pain is bad enough to disrupt your normal activities and your sleep, but you can tolerate it for hours or days. Moderate can also mean pain that comes and goes even if it's severe when it's there.
- Mild pain (1 to 4): You notice the pain, but it is not bad enough to disrupt your sleep or activities.
Pain in children under 3 years
It can be hard to tell how much pain a baby or toddler is in.
- Severe pain (8 to 10): The pain is so bad that the baby cannot sleep, cannot get comfortable, and cries constantly no matter what you do. The baby may kick, make fists, or grimace.
- Moderate pain (5 to 7): The baby is very fussy, clings to you a lot, and may have trouble sleeping but responds when you try to comfort him or her.
- Mild pain (1 to 4): The baby is a little fussy and clings to you a little but responds when you try to comfort him or her.
Symptoms of infection may include:
- Increased pain, swelling, warmth, or redness in or around the area.
- Red streaks leading from the area.
- Pus draining from the area.
- A fever.
Certain health conditions and medicines weaken the immune system's ability to fight off infection and illness. Some examples in adults are:
- Diseases such as diabetes, cancer, heart disease, and HIV/AIDS.
- Long-term alcohol and drug problems.
- Steroid medicines, which may be used to treat a variety of conditions.
- Chemotherapy and radiation therapy for cancer.
- Other medicines used to treat autoimmune disease.
- Medicines taken after organ transplant.
- Not having a spleen.
Symptoms of a severe allergic reaction (anaphylaxis) may include:
- The sudden appearance of raised, red areas (hives) all over the body.
- Rapid swelling of the throat, mouth, or tongue.
- Trouble breathing.
- Passing out (losing consciousness). Or you may feel very lightheaded or suddenly feel weak, confused, or restless.
A severe reaction can be life-threatening. If you have had a bad allergic reaction to a substance before and are exposed to it again, treat any symptoms as an emergency. Even if the symptoms are mild at first, they may quickly become very severe.
You may need a tetanus shot depending on how dirty the wound is and how long it has been since your last shot.
- For a dirty wound that has things like dirt, saliva, or feces in it, you may need a shot if:
- You haven't had a tetanus shot in the past 5 years.
- You don't know when your last shot was.
- For a clean wound, you may need a shot if:
- You have not had a tetanus shot in the past 10 years.
- You don't know when your last shot was.
Shock is a life-threatening condition that may quickly occur after a sudden illness or injury.
Adults and older children often have several symptoms of shock. These include:
- Passing out (losing consciousness).
- Feeling very dizzy or lightheaded, like you may pass out.
- Feeling very weak or having trouble standing.
- Not feeling alert or able to think clearly. You may be confused, restless, fearful, or unable to respond to questions.
Shock is a life-threatening condition that may occur quickly after a sudden illness or injury.
Babies and young children often have several symptoms of shock. These include:
- Passing out (losing consciousness).
- Being very sleepy or hard to wake up.
- Not responding when being touched or talked to.
- Breathing much faster than usual.
- Acting confused. The child may not know where he or she is.
Symptoms of difficulty breathing can range from mild to severe. For example:
- You may feel a little out of breath but still be able to talk (mild difficulty breathing), or you may be so out of breath that you cannot talk at all (severe difficulty breathing).
- It may be getting hard to breathe with activity (mild difficulty breathing), or you may have to work very hard to breathe even when you’re at rest (severe difficulty breathing).
Seek Care Today
Based on your answers, you may need care soon. The problem probably will not get better without medical care.
- Call your doctor today to discuss the symptoms and arrange for care.
- If you cannot reach your doctor or you don't have one, seek care today.
- If it is evening, watch the symptoms and seek care in the morning.
- If the symptoms get worse, seek care sooner.
Seek Care Now
Based on your answers, you may need care right away. The problem is likely to get worse without medical care.
- Call your doctor now to discuss the symptoms and arrange for care.
- If you cannot reach your doctor or you don't have one, seek care in the next hour.
- You do not need to call an ambulance unless:
- You cannot travel safely either by driving yourself or by having someone else drive you.
- You are in an area where heavy traffic or other problems may slow you down.
Call 911 Now
Based on your answers, you need emergency care.
Call 911 or other emergency services now.
Sometimes people don't want to call 911. They may think that their symptoms aren't serious or that they can just get someone else to drive them. Or they might be concerned about the cost. But based on your answers, the safest and quickest way for you to get the care you need is to call 911 for medical transport to the hospital.
Poisonous snake or lizard bite
If you were bitten by a snake or lizard that you know or think is poisonous, call 911 or other emergency services immediately. Do not wait for symptoms to develop. Symptoms may progress from mild to severe rapidly.
If you are not sure what type of snake or lizard bit you, take a picture of it. But do not do this if it will delay treatment or put someone at risk for more bites. Do not waste time or take any risks trying to kill or bring in the snake. Only trap a poisonous snake if the chances are good that it will bite more people if you let it go. It is important to remember that a snake only injects part of its venom with each bite, so it can still hurt you after the first strike. And a dead snake, even one with a severed head, can bite and release venom by reflex action for up to 90 minutes after it dies.
Medicine (antivenom) to counteract the effects of the poison can save a limb or your life. Antivenom is given as soon as a doctor determines it is needed, usually within the first 4 hours after the snakebite. Antivenom may be effective up to 2 weeks or more after a snakebite.
Immediate home treatment
Immediate home treatment should not delay transport for emergency evaluation.
- If you think the snake bite is an emergency, call 911.
- Remain calm and try to rest quietly.
- If you are not sure what type of snake or lizard bit you,call a Poison Control Center immediately to help identify the snake or lizard and find out what to do next.
- Remove any jewelry. The limbs might swell, making it harder to remove the jewelry after swelling begins.
- Use a pen to mark the edge of the swelling around the bite every 15 minutes. This will help your doctor estimate how the venom is moving in your body.
Avoid these treatment measures
Avoid doing anything that might cause more problems with the snake or lizard bite.
- Do not cut the bite open.
- Do not suck on the bite wound or use any kind of extraction device.
- Do not use a constriction band, such as a tourniquet or bandage, on a bite.
- Do not soak your hand or foot in ice water or pack your arm or leg in ice. This can increase damage to the skin and cause a cold-induced injury, such as frostbite.
- Do not raise the bitten arm or leg above your head. This may increase the flow of venom into the bloodstream.
- Do not drink alcohol.
- Do not give any prescription or nonprescription medicines after a poisonous snake or lizard bite unless your doctor tells you to. Some medicines, such as aspirin, ibuprofen, or naproxen, may cause increased bleeding.
Nonpoisonous snake or lizard bite
If you are certain the snake or lizard was not poisonous, use home treatment measures to reduce symptoms and prevent infection.
- Use direct pressure to stop any bleeding.
- Look at the wound to make sure a snake or lizard tooth is not in the wound. If you can see a tooth, remove it with tweezers, taking care to not push it farther into the wound.
- Clean the bite as soon as possible to reduce the chance of infection, scarring, and tattooing of the skin from dirt left in the wound. Wash the wound for 5 minutes with large amounts of clean warm water.
- Do not use rubbing alcohol, hydrogen peroxide, iodine, or Mercurochrome, which can harm the tissue and slow wound healing.
- Soak the wound in warm water for 20 minutes, 2 to 4 times a day, for the next 4 to 5 days. The warmth from the water will increase the blood flow to the area, which helps reduce the chance of infection.
- Puncture wounds usually heal well and may not need a bandage. You may want to use a bandage if you think the bite will get dirty or irritated.
- Clean the wound thoroughly and cover it with a thin layer of petroleum jelly, such as Vaseline, and a nonstick bandage.
- Apply a clean bandage when it gets wet or soiled.
- Determine whether you need a tetanus shot.
- An ice or cold pack may help reduce swelling and bruising. Never apply ice directly to a wound or the skin. This could cause tissue damage.
Try a nonprescription medicine to help treat your fever or pain:
Be sure to follow these safety tips when you use a nonprescription medicine:
Symptoms to watch for during home treatment
Call your doctor if any of the following occur during home treatment:
- Symptoms of a skin infection develop.
- Symptoms become more severe or more frequent.
Snakebites are more likely to occur in warm-weather months when both snakes and people are more active outdoors. Most snakebites occur on the fingers, hands, and arms when someone is working with or trying to catch a snake. The legs and feet are also common bite sites; these bites usually occur when a person (especially a child or a hiker) accidentally disturbs a snake.
Snakes and lizards are popular exotic pets, so the risk for being bitten has increased.
Many snake and lizard bites can be prevented.
- Find out what local snakes and lizards are found in your area. Learn what they look like, whether they are poisonous, and where you are most likely to see them.
- If you see a snake or lizard, do not bother it. Keep in mind that the striking range of a snake is about two-thirds of its length.
- Do not pick up or handle snakes. Even a dead snake can bite and release venom through reflexes for 90 minutes or more after it dies.
- Watch for snakes around wood or rock piles or caves. Wear protective shoes, boots, and clothing when you are hiking, camping, fishing, and hunting.
- Do not drink alcohol or use illegal drugs while doing outdoor activities where you might encounter a snake. The effects of the alcohol and drugs may slow your judgment and reflexes.
- If you have a pet snake or lizard or are thinking about getting one, learn how to handle it safely to avoid being bitten. Find out what first aid supplies you will need if you are bitten, and have them handy.
If you are often in an area where there are poisonous snakes, consider carrying a first aid kit. Carry a cellular phone, if you have one, to call for help if you are bitten.
Preparing For Your Appointment
To prepare for your appointment, see the topic Making the Most of Your Appointment.
Questions to prepare for your appointment
You can help your doctor diagnose and treat your condition by being prepared to answer the following questions:
- Do you know what type of snake or lizard bit you? What did the snake or lizard look like? How big was the snake or lizard? Did it rattle?
- When did the bite occur?
- Where were you bitten?
- How many times were you bitten?
- What are your main symptoms? How long have you had your symptoms?
- What home treatment measures have you tried? Did they help?
- What nonprescription medicines have you tried? Did they help?
- Have you been treated for a snakebite in the past? If yes, what type of treatment did you receive?
- What prescription and nonprescription medicine do you take?
- How long ago was your last tetanus shot?
- Do you have any health risks?
Current as of: October 19, 2020
Author: Healthwise Staff
William H. Blahd Jr. MD, FACEP - Emergency Medicine
Adam Husney MD - Family Medicine
Kathleen Romito MD - Family Medicine
Sean P. Bush MD, FACEP - Emergency Medicine, Envenomation Specialist
To learn more about Healthwise, visit Healthwise.org.
© 1995-2021 Healthwise, Incorporated. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.