What is the cause of chronic nephritis in young people?

Nephritis generally have acute and chronic points, chronic nephritis generally slow onset, in the onset of blood pressure will appear, abnormal urine, body floating and other symptoms. What are the causes of chronic nephritis?
First, the history of nephritis in the past, due to improper life, or infection, tired caused by.
Second, the history of nephritis in the past, due to infection, improper diet leaving patients with significant edema and a lot of proteinuria and other symptoms of nephrotic syndrome.
Third, developed by the acute nephritis, the general cure of acute nephritis weeks or months, the patient's clinical symptoms and abnormal urine disappeared, normal renal function. After a long period of time, due to upper respiratory tract or other infections or overwork, suddenly appear proteinuria, edema or (and) hypertension and nephritis symptoms.

Fourth, by the acute glomerulonephritis onset, this cause is beyond control, the patient in the clinical symptoms and urinary protein persist, extended more than 1 year, and evolved into chronic nephritis.