1The female urethra is short, the bacterium is easy to invade, the infection opportunity is many, therefore the female incidence rate is 8~10 times higher than the male.
2.Urethral mouth has the existence of E. coli, sexual intercourse is often an important cause of infection.
3.Women with estrogen secretion, ureter tension decreased peristalsis is abate, cause urinary tract smooth, urine reflux and higher incidence of the urinary tract infection during the pregnancy, the majority of kidney and kidney tonifying nephritis nephritis. By ascending infection caused by cystitis, especially bladder ureteral reflux, is an important reason for ascending infection.
4.]Inflammation, such as failure to timely or adequate treatment, about 30~50% can cause pyelonephritis
5.Obstruction, such as urinary stones, tumors, stenosis, prostatic hypertrophy and neurogenic bladder, resulting in poor urine flow, local antibacterial ability decrease, is conducive to infection and increased pressure, is an important cause of pyelonephritis. Urinary tract obstruction is approximately 60% of the complicated pyelonephritis.
6.Pathological changes, such as glomerulonephritis, renal cysts, renal tumors and chronic tubulointerstitial disease, can reduce the local antibacterial ability of the kidney, which is easy to be complicated with renal nephritis
7.Factors, such as diabetes, hypertension, chronic low blood potassium, heart failure and many chronic wasting disease complicated with renal pelvis nephritis. Some scholars believe that in addition to ascending infection, renal pelvis nephritis can through the blood and lymphatic organs and near direct infection and immunity, there is a certain relationship.