Bites & stings
Spider Bites
Most UK spider bites are harmless — clean the area, apply a cold compress and take pain relief; see a doctor if it becomes infected or you feel unwell.
When to call 999. Call 999 for any severe reaction — difficulty breathing, facial or throat swelling, or collapse — or if bitten abroad by a spider known to be dangerous. Most UK spider bites cause only local redness, swelling and pain.
What to do
- Clean the bite with soap and water.
- Apply a cold compress (ice wrapped in a cloth) for up to 20 minutes to reduce pain and swelling.
- Raise the affected area if possible to limit swelling.
- Take pain relief such as paracetamol, and an antihistamine can help itching.
- Avoid scratching, which can lead to infection.
- Keep an eye on the bite over the next few days.
Avoid
What not to do
Do not scratch the bite or apply unproven remedies, and do not panic — serious effects from UK spiders are very rare. Do not ignore spreading redness, increasing pain or feeling unwell, which may need medical attention.
Afterwards and while you wait
Most spider bites settle within a few days. See a doctor if the area becomes increasingly red, swollen, painful or oozes pus (signs of infection), if a blister or ulcer forms, or if you feel generally unwell. Bites abroad from known dangerous spiders need prompt medical care.
Education and reference only. This is general first-aid information aligned with UK guidance, not a substitute for a hands-on first-aid course or professional emergency care. In a life-threatening emergency, call 999 straight away.
Answers
Spider Bites: frequently asked questions
Are UK spider bites dangerous?
Very rarely. Most UK spiders cannot pierce the skin or cause only mild local redness, swelling and pain. Serious reactions are uncommon, though a bite can occasionally become infected and need treatment.
How do I know if a spider bite is infected?
Watch for spreading redness, increasing pain, swelling, warmth or pus, and feeling unwell or feverish. If these develop, see a doctor, as the bite may need antibiotics.
Related
Other bites & stings first aid
Sources
Where this is drawn from
- NHS — first aid
- St John Ambulance / British Red Cross first-aid guidance
- UK Health Security Agency (where relevant)
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