Vasovagal response is any cause of fainting related to the function and mediation of the vagus nerve. In a patient with the condition, one or more specific trigger stimuli can quickly lead to light-headedness, nausea, a feeling of being very hot or very cold and, in most cases, fainting. There can be dozens of triggers to the condition, but most patient have just a single trigger. Some of the more common are standing or sitting upright for an extended period of time, urinating while standing up, standing up quickly, stress, arrhythmia, trauma, pain and extreme emotional response.