The Inflammation of the kidney due to infection is called Pyelonephritis.
There are two types of pyelonephritis-Acute and Chronic.
Acute Pyelonephritis is sudden, severe infection and swelling of kidney usually due to bacterial infection, most commonly gram-negative organism like Escherichia coli. It might lead to complications if not treated in time like pus within the kidney, sepsis, or kidney failure.
Chronic Pyelonephritis is caused by recurrent or persistent infection of the kidney leading to renal inflammation and scarring over a period and almost associated with major anatomic anomalies (like Vesicoureteric Reflux).
Symptoms often include
Laboratory tests includes examination of urine sample for bacteria and Drug sensitivity for the same.
Also, Patient needs other blood tests to rule out sepsis and imaging (USG/CT scan) to ascertain cause of pyelonephritis.
In rare cases it can lead to septic shock and multi organ failure.
Remember, kidney infections are not contagious, antibiotics are the first step towards pyelonephritis, usually broad-spectrum antibiotics are used till Urine culture and sensitivity results are available.
Drugs can cure the infection within 4 to 5 days, prescribed medications must be taken for the entire period of course.