In clinical practice, we often encounter diabetic patients who present with non-specific symptoms such as fever, nausea, stomach discomfort, high blood glucose, no other conscious symptoms, and high white blood cells in the blood picture. When they encounter emergency physicians who are unfamiliar with diabetes, they sometimes admit them to the gastroenterology department with acute gastroenteritis, but actually make a big mistake. Why is this so? First of all, we know that one of the main acute complications of diabetes is infection. The reason for this is that high blood sugar causes a significant decrease in the wandering, phagocytic, and bactericidal functions of neutrophils, and the immune function of the body is significantly reduced, making it susceptible to various infections, of which urinary tract infections have the second highest incidence among infectious diseases combined with diabetes, second only to lung; most of these patients we mentioned above suffer from asymptomatic urinary tract infections due to poor blood sugar control. Most of these patients suffer from asymptomatic urinary tract infections due to poor blood glucose control, which induce the occurrence of diabetic ketosis. What kind of diabetic patients are prone to urinary tract infections? (1) Patients with high blood glucose levels and poor control. Because these diabetic patients have high levels of glucose in the blood and urine, glucose is the main nutrient for bacteria and provides a perfect environment for bacteria to flourish. (2) People with relatively long duration of diabetes and advanced age group. The decrease in estrogen and progesterone levels in older women reduces the pH of the female genitourinary tract and thins the mucous membrane of the urinary tract, making it susceptible to urinary tract infections; prostate disease in older men, including prostatic hyperplasia and bacterial prostatitis, increases significantly, resulting in poor urinary drainage and increased residual urine, making it easy for bacteria to retrograde into the bladder and cause disease. The incidence of urinary tract infections can be above 9O% in patients with longer duration of disease due to the development of vegetative neuropathy and the formation of diabetic neurogenic bladder. (3) Female patients have special physiological and anatomical characteristics of the urethra (short and wide urethra) and are more prone to urinary tract infections than men. (4) Combined diabetic nephropathy. Patients with diabetic nephropathy are more prone to urinary tract infections than those with other comorbidities. This may be due to protein excretion from the urine, which reduces serum protein levels and resistance, and in some patients, impaired renal function, reduced urine volume, and weakened flushing of bacteria through urination. What are the characteristics of diabetes mellitus combined with urinary tract infection? (1) Insignificant symptoms of urinary tract irritation; as we mentioned earlier, these patients do not have symptoms of bladder irritation such as urinary frequency, urinary urgency and pain, but they do suffer from urinary tract infection by laboratory tests of urine. Asymptomatic may be related to the prolonged course of diabetes combined with peripheral neuropathy and vegetative neuropathy that reduce local sensitivity and irritation, or it may be related to unresponsiveness in the elderly, overlapping symptoms of multiple diseases, and hyperglycemia and polyuria that mask the symptoms of bladder irritation. Other studies have suggested that because of the reduced immune function and decreased production of urinary tract cytokines (such as interleukin 6) in diabetic patients, the clinical manifestations of urinary frequency, urgency, painful urination, fever, and elevated leukocytes are less likely to occur than in non-diabetic patients, and more often manifest as asymptomatic bacteriuria. (2) Because of the lack of symptoms, it cannot be detected in time, which leads to prolonged inflammation and delayed treatment. There are some diabetic patients with recurrent urinary tract infections, which are related to irregular and incomplete treatment and the development of drug resistance of bacteria. Therefore, urinary tract infections in combination with diabetes mellitus are characterized by high incidence, insidious onset, easy recurrence, and the need for comprehensive treatment. (3) Since the majority of urinary tract infections are exogenous upstream infections, the pathogenic bacteria of diabetic combined urinary tract infections are mainly G-bacteria (retrograde infection of intestinal bacteria), followed by G+cocci, and a small proportion of fungi. Clinically, a significant proportion of type 2 diabetic patients with urinary tract infections have no conscious symptoms, but are only detected during routine urinalysis, and these asymptomatic diabetic patients are the ones who are easily overlooked. It may even lead to ketoacidosis, hyperosmolar coma and infectious shock and even death. Therefore, for diabetic combined urinary tract infection, we internal medicine doctors and diabetic patients should pay high attention to it, be vigilant in the process of treatment, and take active and effective preventive and control measures: (1) actively control blood sugar, and actively treat various complications. (2) Develop good hygiene habits, drink more water, urinate more often, and keep the vulva clean. (3) Press the lower abdomen when urinating if you have neurogenic bladder to promote urine elimination. If urinary retention is serious, catheterization should be given to make bacteriuria discharge as soon as possible to facilitate infection control. However, the number of intubations and retention time should be minimized, antibiotic bladder irrigation should be given, and nerve-nourishing drugs such as methylcobalamin should be applied. After the infection is controlled, suprapubic cystostomy can be considered. (4) Regular urinary routine examination for early detection and early treatment. Once a urinary tract infection is detected, urine bacterial culture and drug sensitivity should be done first, and then sensitive antibacterial drugs should be selected, avoiding the blind use of antibacterial drugs without doing urine culture. Otherwise, it will not only affect the treatment effect, but also cause bacterial resistance, dysbiosis and secondary infection. It should be emphasized that acute pyelonephritis is the most common clinical type of urinary tract infection in diabetes, and pyelonephritis is an important cause of deterioration of renal function in diabetic patients. For urinary tract infections, especially acute pyelonephritis, blood glucose control should be treated with insulin and 2 or more broad-spectrum antibiotics in combination to control the disease as soon as possible and prevent deterioration, and the course of treatment should be long, preferably more than 2 weeks. After discontinuation of the drug, it is still necessary to repeatedly take the middle urine culture, and 3 consecutive negative times to be considered cured, otherwise it is easy to relapse. (5) For the combination of kidney disease and renal insufficiency caution or prohibit drugs that damage the kidneys, such as quinolones, aminoglycoside antibiotics.