Snake Bite Symptoms

Usually, people know right away if a snake has bitten them. However, these animals can strike quickly and disappear before people have time to react.

Most snake bites can cause pain and swelling around the bite. Those that are venomous may also cause fever, a headache, convulsions, and numbness. However, these symptoms can also occur due to intense fear following the bite.

Bites can cause an allergic reaction in some people, which may include anaphylaxis.

All venomous snakes can deliver dry bites, which are bites that do not inject venom. They do this because they have limited venom stores, so they save venom where possible. According to estimates, 20–25 percent of pit viper bites and 50 percent of coral snake bites are dry bites.

Symptoms of a venomous snakebite

Venomous snakes have two fangs that deliver venom when they bite. A venomous snake bite will usually leave two clear puncture marks. In contrast, a nonvenomous bite tends to leave two rows of teeth marks.

It can be difficult to tell the difference between puncture wounds from venomous and nonvenomous snakes. People should seek medical attention for all snake bites.

The symptoms of a venomous snakebite depend on the type of toxin(s) secreted into the bite or puncture wound, and in part, on how much toxin is present in the tissue.

The types of symptoms produced can be grouped into four groups:

  • Cardiotoxins act on heart tissue.
  • Neurotoxins act on nervous system tissue.
  • Cytotoxins act on tissue at the site of the bite or on tissue that directly absorbs the venom.
  • Hemotoxins act on the blood coagulation system and may cause internal bleeding.

Some toxins may cause more than one of these effects. Because of the various symptoms that can occur with venomous snakebites, the potential signs and symptoms to look for,

Typical symptoms of a venomous snake bite include:

  • A pair of puncture marks at the wound
  • redness and bruising around the bite area
  • swelling around the bite
  • Severe pain at the site of the bite
  • Nausea and vomiting
  • Abnormal blood clotting and bleeding
  • Low blood pressure and shock
  • Labored breathing (in extreme cases, breathing may stop altogether)
  • Disturbed vision
  • Increased salivation and sweating
  • Numbness or tingling around the face and/or limbs, especially in the mouth
  • elevated heart rate
  • dizziness
  • weakness
  • headaches
  • fever
  • thirst
  • diarrhea
  • fainting
  • convulsions

Symptoms from these toxins are somewhat variable and may occur quickly within minutes or they may be delayed for hours, depending on the toxin type and the amount absorbed. In general, small children are more vulnerable to snake bites because the relative larger amount of toxin absorbed in relation to their smaller body size can make the toxin effect more potent. Individuals with medical conditions like heart disease or other chronic diseases are also at higher risk of complications due to snakebite. The quick action of many toxins usually does not allow the immune system a chance to counter the toxin’s effects.

Identification of the snake helps emergency health care professionals to both anticipate the potential symptoms, and it allows for more rapid and appropriate treatment of the venomous snake bite. A detailed description and a picture of the snake will help identify the type of snake and the type of toxin. Do not waste time, however, in transporting the patient to an appropriate medical facility and do not put others in jeopardy of getting bitten.


Rattlesnakes are easily identifiable. They have rings at the end of their tails that shake when they feel threatened. This makes a rattling sound and is a warning for you to back away. Rattlesnakes are the largest of the venomous snakes and account for many of the venomous bites in the U.S. each year. These snakes can be found in nearly any habitat across the country. They like open areas where they can rest in the sun such as rocks, and logs.


Symptoms specific to rattlesnake bites are immediate and include:

  • severe pain
  • drooping eyelids
  • low blood pressure
  • thirst
  • tiredness or muscle weakness

Water moccasins or cottonmouths

The water moccasin is another type of pit viper. This snake is also known as a cottonmouth, because the inside of its mouth is lined with a white, cottony material. The water moccasin’s average size is between 50 to 55 inches. Adults have dark tan to black skin with faint dark brown or black crossbands. Young snakes have brown or orange crossbands with a yellow tail. These snakes are found in the southeastern states, usually in or near water. They don’t scare easily, and will defend themselves should they feel threatened.


Water moccasin bites share symptoms with copperhead bites. Specific symptoms include:

  • immediate pain and symptoms
  • change in skin color
  • shock
  • low blood pressure
  • weakness


Copperheads are reddish or gold in color with hourglass-shaped bands. This snake is typically 18 to 36 inches in length. Copperheads are mostly found in forests, swamps, rocky areas, and rivers in the eastern states (as far as Texas). They are not aggressive. Most copperhead bites occur if you accidentally step on or near one.


Copperhead snake bites share symptoms with water moccasin snake bites. Symptoms can include:

  • immediate pain and symptoms
  • change in skin color
  • shock
  • low blood pressure
  • weakness

Coral snakes

Coral snakes have black, yellow, and red banding and are often confused with non-venomous king snakes. You can distinguish a coral snake by the fact that the red bands touch the yellow bands. They live in the woods, marshes, and sandy areas of the South. Coral snakes typically hide underground and in leaf piles.


Symptoms specific to coral snake bites include:

  • pain that is not immediate
  • symptoms that set in hours after the bite
  • convulsions
  • drooping eyelids
  • change in skin color
  • stomach pain
  • difficulty swallowing
  • headache
  • shock
  • paralysis


Symptoms of nonvenomous snake bites

Nonvenomous snakes do not produce toxins. Unlike venomous snakes, they do not have fangs. Instead, they have rows of teeth.

Some symptoms of nonvenomous snake bites include:

  • pain near the bite area
  • bleeding
  • swelling and redness near the bite area
  • itching near the bite area

Without treatment, nonvenomous bites can lead to skin infections and necrosis, or tissue death, so it is essential to look after the wound. Bites can also cause allergic reactions in some people.

The World Health Organization (WHO) has listed snakebite to its list of neglected tropical diseases. Sub-Saharan Africa has a lack of antivenom supplies; minute-to-minute delays in treatment can affect outcomes; for example in April 2019, a woman died on her wedding day a few hours after a snakebite in Nigeria.