Feeling tired lately? Has the doctor said he cannot find anything wrong with you? Perhaps he sent you to a hospital, but all the advanced equipment there shows that there is nothing wrong. Then consider this, you might be in a state of subhealth( 亚健康 ). Subhealth, also called the third state or grey state, is explained as a border line state between health and disease. According to an investigation by the National Health Organization, over 45 percent of subhealth people are middle aged or elderly. The percentage is even higher among people who work in management positions as well as students around exam time. Symptoms include a lack of energy, depression, slow reactions, insomnia, agitation and poor memory. Other symptoms include shortness of breath, sweating and aching in the waist and legs. The key to preventing and recovering from subhealth, according to some medical experts, is to form good living habits, alternate work with rest, exercise regularly, and take part in open-air activit i es. As for meals, people are advised to eat less salt and sugar. They should also eat more fresh vegetables, fruits, fish, because they are rich in nutritional elements- vitamins, and trace elements— that are important to the body. Nutrition experts point out that it is not good to eat too much at one meal because it may cause unhealthy changes in the digestive tract. They also say that a balanced diet is very helpful in avoiding subhealth.pianzh