A brown adder in heather

Advice on Adder Bites

Last updated: April, 2021

Advice on Adder Bites

In this article we’ll discuss bites from Adders – the UK’s only venomous snake, and something you may well see if out walking, if you are lucky! They usually like to bask in the sun on rocks, and will be more surprised to see you than you are of it! They often sense you approaching and will move away before you even know they are there. If you do see one, stay calm, keep your distance and let it move away in it’s own time.

Often its dogs that disturb Adders, and bites can be quite dangerous for smaller dogs, but much less so for humans. Adders may strike if cornered or harassed.

What does an adder look like?

A grey adder showing its eye in detail
Adders have a distinctive diamond pattern
A brown adder in heather
Adults are between 40-70cm (16-28inches) long
A black adder
They may be grey, brown or rarely, black, like this one.

What to do if someone is bitten by an Adder

1. Stay Calm

If someone gets bitten: most importantly – don’t panic, stay calm. It is likely that only a small amount of venom has actually been injected. However, minimising a casualty’s movements limits the pumping of any venom around the blood system and towards the heart. That is where it can do serious damage and pump the venom throughout the bloodstream to other vital organs.

2. Clean the bite

The area of the bite should be washed to remove any venom from the skin. Use clean water or a medi-wipe. You might put a ‘cold compress’ on the bite site but do not apply ice packs. A cold compress could even be bandage or other material soaked in cool water. This will help limit the spread of the venom and relieve any pain.

3. Keep the bite low

Keep the bitten limb below the heart height to slow spread of any venom. Assuming it is their leg that has been bitten, sit the casualty down on a rock, tree stump, or backpack, with their leg downhill. Loosen clothing on the affected limb and remove jewellery.

If the casualty has more serious reactions, call 999/112 and get an ambulance. Put the casualty in the Recovery Position and lower the affected limb below the level of the heart. In rare occasions, some people may have an anaphylactic reaction or suffer high anxiety leading to breathing problems.

Monitor their vital signs regularly. It’s good practice to note these down and hand them to the ambulance service when they arrive. You can download a free Casualty Monitoring card from our website.

4. Avoid ‘bad’ first aid!

Most ‘traditional’ first-aid techniques (that you may have seen in films!) do more harm than good. For example, cutting into the wound is harmful and why would you want to suck up the poisoned blood and put poison into your own system? Tourniquets are dangerous and shouldn’t be used in these circumstances. New fangled suction and electrical inactivation devices you may have seen advertised have no evidence showing they work effectively. Sensible first aid, lots of reassurance and emergency medical care is what is required.

5. Reassure the casualty and seek medical support.

It is likely the bite will be painful, cause swelling, tingling and distress. However as long as the casualty doesn’t have an underlying health problem they should be OK. Let the casualty take their time, after an initial period of 20-30 minutes the casualty may stand slowly and start to walk out with support and head for the nearest A&E Department.

Make sure you know exactly where you are and where the nearest road access is for the ambulance. Use a grid reference finder app (such as OS locate) on your phone or the ‘What3words‘ app.

What are the signs and symptoms of an adder bite?

The signs and symptoms will vary with the health and fitness of the casualty but generally are:

  • 2 puncture wounds although sometimes there may be 1 or 3!
  • numbness and tingling around the wound
  • nausea and drowsiness
  • Rarely – anaphylactic shock

Adders use their venom to subdue their prey, mainly lizards and small mammals. The venom is designed to incapacitate their prey by causing haemotoxic effects which effects their blood cells and tissues.

Sometimes they do ‘dry bites’ where no venom is injected, although you may still have some symptoms from the bite area. First aid response is the same as above as you won’t know if venom has been injected or not until you are assessed in hospital. It has been known for people to not realise they’ve been bitten by an adder. They may have sat down near it without seeing it and felt a sharp ‘scratch’ and thought it was vegetation. However, the symptoms will soon appear and should alert you to the possibility that this person has been bitten by an adder.

Can you die from an adder bite?

Statistically you have more chance of being killed by a wasp than dying from an adder bite. The last death from an adder bite in the UK was in 1975. Since then, quicker response times from emergency services and increased awareness of the public means that an adder bite today will probably mean a trip to the hospital and possibly an overnight stay for observations. Very rarely, people have severe reactions to the venom so it’s always best to seek medical advice if someone is bitten.

What about children, the elderly or people with underlying medical conditions?

If the casualty is a child or an elderly adult there would be more concerns. Their smaller body weight means any toxins would have a greater effect so it would be recommended that you call 999/112 straight away. also, people with underlying medical conditions may react differently or not be able to suppress the venom. However the advice above still remains the same. Keep calm, avoid lots of movement, reassure the casualty and get medical help as soon as possible. Remember to mention the age or vulnerability of the casualty when you call.

Don’t chase the snake!

The snake will have struck in self defence and very likely disappeared very quickly. Do not be tempted to try and catch it. If you caught site of it and can describe it to the medical professionals that will help, but don’t worry if you aren’t able to. The casualty is likely to have quite clearly identifiable puncture wounds with which the injury can be recognised.

What if it’s not an adder?

You don’t have to identify the snake before you call 999. A swab will be taken at the hospital to identify the venom, if any, and treat you accordingly.

The zig zag pattern on the adder is distinctive. If it does not have this it could be one of the species below.

Slow worm – these are actually legless lizards and are smaller, generally 30-40 cm with a smooth brown skin with darker markings down the sides. They are found throughout the UK.

Other snakes found in the southern parts of the UK are the grass snake and smooth snake. Grass snakes are large, typically 70 – 100 cm and can be identified by their distinctive black and yellow markings behind the head. Smooth snakes are rare and small at only 45 – 55 cm,. They are grey-brown with bars or paired blotches along its back. Smooth snakes are only found in a limited geographic area in the southern part of England.

If it’s not one of these (remember, don’t chase it to identify it!) it may be an escaped pet or from a zoological collection. Most pet snakes are not venomous but can still cause a local reaction such as swelling or irritation.

A slow worm in a meadow
A slow worm is a small shiny legless lizard (not a snake) and is only 40-50cm (16-28 inches) long. It has eyelids unlike snake species. Males are greyish brown and females (above) are brown with darker sides.
A grass snake showing its  distinctive yellow and black collar
Grass snakes have a distinctive yellow and black collar and can grow to over 1 metre (3feet) in length and hence are generally larger than adders.
A smooth snake showing the grey brown head and curled up body
A smooth snake is brown grey with bars or blotches along its back. At 45-55cm (just over a foot in length) they are small snakes compared to an adder.
(Picture by Chris Dresh, Amphibian and Reptile Conservation)

Our digital Outdoor First Aid manual covers adder bites and other wildlife hazards such as poisonous plants, sea creatures and environmental hazards such as heat stroke, hypothermia and altitude sickness. Everyone on our outdoor courses receives one free. We also produce manuals for equestrian, paediatric, sports and workplace settings. All available for just under £4 via our on line shop