Snakes sometimes bite in self-defence if they are disturbed or provoked. Adders, or vipers, are the only wild venomous snakes in the UK.
This article focuses on the bites of adders. See the Health A-Z topic about Snake bites (foreign) for more information about other types of snake bites.
Adders are found in:
- mainland England
- the Isle of Wight
- Wales
- Scotland
- some of the Inner Hebridean Islands (a group of islands off the west coast of Scotland)
Adders sometimes bite without injecting any venom (toxins produced by the snake). This is called a ‘dry’ bite and may cause:
- mild pain caused by the adder’s teeth puncturing the skin
- anxiety
If an adder injects venom when it bites it can cause more serious symptoms including:
- swelling and redness in the area of the bite
- nausea (feeling sick)
- vomiting
- faintness
See Snake bites, adder - symptoms for more information.
How common are snake bites?
In the UK, the adder is the only venomous snake that is found naturally in the wild. See Snake bites, adder - causes for more information about adders.
Each year, approximately 100 cases of adder bites are reported in the UK. Most bites occur between February and October, with the number of bites peaking during the summer months.
Worldwide, there are around 5 million snake bites every year.
Outlook
Adder bites can be painful but they are rarely serious. About 7 out of 10 adder bites only result in pain and swelling in the area that has been bitten. Since records began in 1876 there have only been 14 reported deaths as a result of adder bites, with the last death occurring in 1975.
Severe cases of adder bites are unusual, but they can be treated effectively in hospital using anti-venom medicine. See Snake bites, adder - treatment for more information.
