Going out and seeing dog shit will feel nauseous to come back to wash feet and hands, may be caused by psychological disorders, such as obsessive-compulsive disorder, cleanliness and so on. 1. Obsessive-compulsive disorder: is a relatively common clinical psychological disorder, mainly manifested in the patient’s fear of their own hands or body to touch the dirty things, and worried about bacteria, so usually caused by seeing dog shit will feel nausea, come back to wash their feet to wash the reaction, serious and may be local disinfection, patients will also repeat or stereotyped repeat a certain kind of action. Diagnosed as obsessive-compulsive disorder, should be carried out as soon as possible psychotherapy, if necessary, can follow the doctor’s instructions oral risperidone, aripiprazole and other drug therapy. 2. Cleanliness: the main manifestation of excessive love of cleanliness, some patients because of obsessive-compulsive disorder development, but may also be caused by other psychological disorders, mainly manifested in the constant washing of hands, feet, washing life objects, can not tolerate their own body will touch the dirty things. These patients may often practice stepping on sand, or often fantasize about dirty environments. However, normal people who go out and see dog shit feel will also feel nausea, if there is no other pathological reaction, generally do not need special treatment, if the appearance of uncontrollable behavior should be timely medical care.