stress, such as from being dehydrated, extremely overheated, donating blood, seeing blood or gore, etc. However, some
people have cardiac conditions or neurological conditions which predispose them to
fainting; these may cause the person to faint under circumstances which would not cause a healthy person to faint, or might lower the "threshhold" for fainting such that it requires much less of the typical stressors on the body to induce fainting (or near fainting).