Arachnophobia is an intense, persistent fear of spiders and other arachnids (eight-legged creatures like scorpions and ticks). While many people feel a little uncomfortable around spiders, someone with true arachnophobia experiences overwhelming anxiety or panic, even when they know logically that most spiders are harmless.

The word combines arachne, the Greek word for spider, with phobia, meaning an extreme fear. In Greek mythology, Arachne was a weaver who challenged the goddess Athena to a contest and was transformed into a spider.

A person with arachnophobia might freeze when they spot a spider, refuse to enter a room where they saw one earlier, or have nightmares about spiders. The fear can seem irrational to others: a tiny spider that couldn't possibly hurt them might trigger the same panic response as a genuine danger. Some people with severe arachnophobia even react to pictures of spiders.

Arachnophobia is one of the most common specific phobias. Scientists think it might be partly evolutionary: our ancestors who stayed alert around potentially venomous creatures survived better. But for most people today, this ancient instinct is far stronger than necessary. Therapists can help people overcome arachnophobia through gradual exposure and learning to manage their fear response.