糖尿病是一组以慢性血糖水平增高为特征的代谢性疾病群，除碳水化合物外，还存在蛋白质、脂肪代谢的异常。其基本病理生理为绝对或相对胰岛素分泌不足所引起的代谢紊乱，以高血糖、糖尿、葡萄糖耐量减低及胰岛素释放试验异常为特征。
Diabetes mellitus is a group of metabolic disorders characterised by chronically elevated blood glucose levels. In addition to carbohydrate metabolism abnormalities, disturbances of protein and fat metabolism are also present. The basic pathophysiology involves metabolic disorders caused by absolute or relative insulin deficiency, characterised by hyperglycaemia, glycosuria, impaired glucose tolerance, and abnormal insulin secretion test results.
临床上早期可无症状，至症状期才出现多食、多尿、烦渴、善饥、消瘦、疲乏无力等症候群，久病者可引起多系统损害，导致眼、肾、神经、心脏、血管等组织慢性进行性病变，引起功能缺陷及衰竭。
Clinically, the early stage may be asymptomatic. As the disease progresses, symptoms such as excessive eating, excessive urination, excessive thirst, persistent hunger, weight loss, fatigue, and weakness may appear. Long-standing disease may lead to multi-system damage, causing chronic progressive disorders affecting the eyes, kidneys, nerves, heart, blood vessels, and other tissues, eventually resulting in functional impairment and organ failure.
症状：三多一少，即多饮（口干思饮，渴饮无度）、多食（消谷善饥，食不知饱）、多尿（尿频量多，夜间尤甚）；少：形体消瘦。其因不一，证有虚实，兼症亦异。
Symptoms: “Three excesses and one deficiency” — excessive thirst (dry mouth with uncontrollable desire to drink), excessive eating (rapid digestion with constant hunger and inability to feel full), excessive urination (frequent and abundant urination, especially at night), and weight loss or emaciation. Causes vary, and syndromes may be classified as deficiency or excess patterns, with different accompanying symptoms.
临床所见多以虚证、热证为多，实证、寒证较少，尤以虚热和气阴两虚之证居多。
In clinical practice, deficiency and heat syndromes are more common, while excess and cold syndromes are less frequent. Deficiency heat and dual deficiency of Qi and Yin are particularly common.