First Aid Facts – Spider Bites

It can be difficult to know if a bite from a spider is dangerous or not.

It is best to medically categorize spider bites into 3 groups:

  1. Big black spiders
  2. Redback spiders
  3. All other spiders

Big black spiders are funnel web spiders and any large black-looking spiders that may be a funnel web spider. Their bites are serious – calm the person, be prepared to provide CPR and call (000) for an ambulance to seek urgent medical assistance.

Redback spiders are easy to identify and their bites do not cause rapidly developing or life-threatening effects but many cause significant pain and other problems in your body.

All other spiders are more or less harmless and no further treatment is required.


How do you know if you have been bitten by a spider?

Look for things like:

  • swelling
  • a red welt
  • skin damage
  • any troubling symptoms that accompany the bite

Other possible symptoms that may accompany a spider bite include:

  • itching or rash
  • pain around the area of the bite
  • muscle pain or cramping
  • blister that’s red or purple in colour
  • sweating
  • difficulty breathing
  • headache
  • nausea and vomiting
  • fever or chills
  • anxiety or restlessness
  • swollen lymph glands
  • high blood pressure


Steps to take if someone gets bitten:

Big black spiders

  1. apply a pressure immobilisation bandage
  2. keep the victim from moving around
  3. keep the bitten limb down
  4. bandage the limb from the area of the bite to the hand or foot, then back up to the body
  5. immobilise the limb by splinting if possible
  6. tell the victim to keep calm
  7. wait for the ambulance

Other spider bites

For all other spider bites, including red-backed spiders, apply a cold compress or ice pack directly over the bite site to help relieve the pain. Seek medical assistance if further symptoms or signs of infection develop.


The St John Ambulance Australia Fact Sheet Managing A Spider Bite