What are the main reasons for sub-health?

Small space: Whether working or living in small conditions or always crowded with buses, these small living and working spaces will cause mental discomfort and pressure. After a long time, they will feel very tired, listless and in a sub-health state. Environmental pollution: the aggravation of environmental pollution, the air is no longer fresh, the water is no longer clear, and vegetables are not necessarily green, all of which affect people's health invisibly. The so-called disease enters from the mouth. Although sub-health status does not mean illness, long-term failure to improve will also lead to disease.