老年人营养不良和其他年龄组一样也分消瘦和恶性营养不良两种类型。消瘦是指热能不足,而蛋白质摄取正常;恶性营养不良是指热能和蛋白质摄取均不足而言。通常将体重下降每周达1％～2％,每月达5％或每半年达10％定为营养不良。老年人恶性营养不良的患病率:在医院和休养所住院的老年人中高达20％～60％。而在乡镇老年人中为5％～10％。主要临床表现有精神错乱、全身无力、低自蛋白血症(低于30g/L)、总铁结合力下降(低于35.6μmol/L)、淋巴细胞减少(少于1×10~3/ml) Elderly malnutrition and other age groups are also divided into two types of weight loss and malignant malnutrition. Weight loss refers to the lack of heat, and protein intake is normal; Malignant malnutrition refers to the heat and protein intake are not enough. Weight loss usually takes 1% to 2% per week, up to 5% per month, or 10% per half year as malnutrition. Prevalence of Malignant Malnutrition in the Elderly: Up to 20% -60% of elderly people hospitalized in hospitals and rest houses. In the township elderly 5% to 10%. The main clinical manifestations were delirium, general weakness, hypoproteinemia (less than 30 g / L), decreased total iron binding (less than 35.6 μmol / L), lymphopenia (less than 1 × 10 -3 / ml )