One kidney is big while the other is small

Everyone has two kidneys, located in the waist. However, as we age, our bodies will become weaker and weaker, especially our kidneys, which will slowly age over time and it is easy for one kidney to become larger than the other. This is a manifestation of nephritis. This situation is often manifested in frequent urination, urgency, and incomplete urination, and abnormalities will also occur in the renal tubules. It must be treated in time, otherwise it will cause uremia.

Pyelonephritis is an inflammation of the renal pelvis and renal parenchyma caused by pathogenic microorganisms, often accompanied by lower urinary tract infection. Most of them are caused by Gram-negative bacteria infection and are divided into two types: acute and chronic. Acute pyelonephritis is manifested by acute interstitial inflammation and tubular necrosis related to infection. Patients have symptoms such as fever, frequent urination, urgency, pain when urinating, and bacteriuria. If there are no complicating factors, it can be quickly cured by using effective antibacterial drugs. Chronic pyelonephritis often occurs on the basis of abnormal urinary tract anatomy or function. In addition to bacterial urine infection, there is also scarring of the renal pelvis and calyces, an uneven kidney shape, or unequal sizes of the two kidneys. The onset is relatively insidious and prone to recurrence, which can lead to chronic renal failure.

The pathogens of this disease are mostly Gram-negative bacteria, with Escherichia coli being the most common. The main route of infection is ascending infection, that is, the pathogenic bacteria ascend from the urethra into the bladder, causing cystitis, and then spread upward along the ureter to the kidneys, causing pyelonephritis. In normal people, there are a small number of bacteria 1 to 2 cm inside the urethral opening, but it generally does not cause infection because the urethral mucosa has a certain antibacterial ability; urine can dilute the bacteria and excrete them out of the body; urine also contains some antibacterial substances. When the body's resistance is reduced or the urethral mucosa is slightly damaged (such as during menstruation, after sexual intercourse, etc.) or the urinary system is deformed and urinary circulation is not smooth (such as ureteral stones, prostate hypertrophy, urethral stenosis, urinary tract tumors, etc.), bacteria take advantage of the situation and multiply in the renal pelvis, causing kidney disease. Because the female urethra is short and wide, the urethral opening of female babies is easily contaminated by feces, so they are prone to the disease.

In a small number of patients, pyelonephritis results from bloodstream infection, with the main pathogens being Staphylococcus aureus, Salmonella, Pseudomonas aeruginosa, and Candida. When the kidney structure is damaged (such as polycystic kidney disease) or patients with diabetes, long-term use of glucocorticoids and immunosuppressants, and other chronic wasting diseases, resistance is reduced and bacteria can easily invade the kidneys through the bloodstream. The lesions are often bilateral.

Chronic pyelonephritis has complex clinical manifestations, is prone to recurrence, and has a hidden course of disease. It may sometimes present as asymptomatic bacteriuria and/or intermittent frequent urination, urgency, and pain when urinating. There may be manifestations of chronic interstitial nephritis, including decreased urine concentrating ability, hypotonic and low specific gravity urine, increased nocturia and renal tubular acidosis. In the late stage, glomerular function damage, azotemia and even uremia may occur.