Itching on the body for no reason can be due to diseases such as pruritus, urticaria and eczema. 1. Pruritus: this disease is only itchy skin without primary lesions, and its most common cause is dry skin. Itching is mostly a burning sensation, and generalized itching is often paroxysmal and aggravated at night; limited itching, localized paroxysmal exacerbation. Because the skin surface has no lesions, no abnormalities, so it will make people feel itchy for no reason. 2. Urticaria: some people are allergic, if accidentally contacted with allergens, it will lead to allergies and cause urticaria, which makes the body always itch for no reason, and the itchy parts of the body will also appear in varying sizes of the wind, the surface of the uneven and so on. 3. Eczema: it is a kind of allergic skin disease, the cause of eczema is still unclear, may be related to genetics, hormonal changes, metabolic diseases, and its performance is mainly for erythema, pimples, skin cracking with itching, and so on. Therefore, when eczema is accidentally suffered, it will be self-conscious about itching for no reason, and in severe cases, there will be plasma oozing from the skin lesions. In conclusion, if the body itchy for no reason, it is recommended to go to the regular hospital in time, clear cause of the symptomatic treatment.