Kidney infection, or pyelonephritis, refers to the inflammation of the kidney caused by a bacterial infection. Common symptoms of a kidney infection include flank tenderness, fever, nausea, dysuria, increased urinary frequency, and more. Severe and advanced cases of kidney infection can lead to complications such as sepsis, kidney failure, and pus around the kidney.
When an infection spreads upwards from the urinary tract – and, less commonly, through the bloodstream – to the kidney, it becomes infected. Kidney infection can be diagnosed based on the symptoms of the patient, urinalysis, and possibly, medical imaging. The risk of developing a kidney infection can be lowered by drinking enough fluids and urination after sexual intercourse. It is usually treated with antibiotics such as ceftriaxone and ciprofloxacin.
Severe cases may require hospital admission, and surgery may be necessary among patients with kidney stones or structural issues in the urinary tract. Pyelonephritis is common and affects approximately 1 to 2 in every 1,000 women and 0.5 per 1,000 men. This condition is most commonly seen among young adult females. It has a good prognosis among young adults, but the risk of death for individuals over the age of 65 is about 40 percent.
Cause #1: Kidney Stones
Kidney stones, or renal stones, occur when solid material remains and builds up in the urinary tract. The material exits the body via the urinary tract out of the urethra. While some individuals experience no symptoms due to smaller stones, stones that are bigger than 5 millimeters can cause blockage in the urinary tract leading to severe pain in the loin or groin, lower back pain, blood in the urine, nausea, vomiting, dysuria, and more.
Risk factors of kidney stones include dehydration, obesity, high levels or calcium in the urine, etc. In case of obstruction, a urinary tract infection (UTI) may occur due to accumulation of bacterial growth in the stagnant urine. From the urethra, the infection can spread upwards toward the bladder, ureters, and kidneys, causing a kidney infection.