In 98% of all cases, spider bites are not considered to be emergencies. According to Medical1Stop.com, symptoms are mild and rarely require a treatment. However, there are situations when poisonous spiders can cause severe and intense reactions. Some patients might experience dizziness, confusion, numbness, thoracic pains or even hemorrhages. In such cases, you need to seek help from the emergency room. The most harmful symptoms include the suggestive state of shock, which can target both kids and adults. When calling the emergency number, communicate all the symptoms, as well as the circumstances. You might be given a few tips before the doctor gets there.