Itching all over the body as soon as you go to bed at night can be pruritus or chronic eczema or chronic urticaria. Pruritus is caused by allergic factors, such as food allergies, respiratory allergies, or itching can be caused by systemic factors, such as diabetes, nephritis, hepatitis, and liver insufficiency. Eczema worsens the itching at night due to allergies or other factors. In addition to these factors, there is also the possibility of neurodermatitis, especially generalized neurodermatitis, where the itching of the whole body is more severe at night.