Arachnophobia can be triggered by the mere thought of a spider or even by a picture of a spider in some cases.
Many people who fear spiders feel panic entering a situation where spiders may be present. This is quite a common phobia known as arachnophobia.
Symptoms include excessive sweating, rapid breathing, a quickened heartbeat, nausea and dizziness.
Some arachnophobics will, on entering a room, search it for a spider. If they find one they will monitor its progress very thoroughly. Others will do all in their power to distract themselves to avoid seeing the spider.
There are historical and cultural reasons for arachnophobia.
In the Dark Ages spiders were commonly considered to be a source of contamination of food and water. They were believed to be the cause of the Bubonic Plague (though in reality rat-fleas were in fact the true culprits). This misplaced fear has been passed down since the 10th Century.
Often the fear is caused by a frightening incident in earlier life.
Sometimes people have the misconception that such a startling event has to be a memorable ordeal. Yet many don't even recall the events that led to their phobia. The mind can create a phobia based on a split second of panic.
The treatment of arachnophobia is called "systematic desensitization".
With the help of a therapist, the sufferer will slowly learn to face their fears. First they will be exposed to pictures of spiders. Later they will come face to face with real spiders. When they are able to hold a live spider without feeling anxious, they will have conquered their phobia.
Advancements in technology have added a new dimension to the treatment of arachnophobics: virtual reality. Now the patient can wear a VR helmet or glasses with a VR glove. With the help of a computer generated spider, they can steadily overcome their fear, moving the VR glove closer until they can "feel" the spider crawl across their hand.