Other ANCA small-vessel vasculitides - The conditions included in this category are eosinophilic granulomatosis with polyangiitis, microscopic polyangiitis, and granulomatosis with polyangiitis. Pathophysiology
The pathophysiology of nephritic syndrome is dependent on the underlying disease process, which can vary depending on what condition the nephritic syndrome is secondary to. More specifically, different diseases (many of which are mentioned above in the Causes section) affect different segments of the glomerulus and cause disease-specific segments of the glomerulus to become inflamed. Most often, it is dependent on what part of the glomerulus is damaged by antibody-antigen complex (immune complex) deposition. In all cases, however, the inflammatory processes in the glomerulus cause the capillaries to swell and the pores between podocytes become large enough that inappropriate contents in the blood plasma (i.e. red blood cells, protein, etc.) will begin to spill into the urine. This causes a decrease in glomerular filtration rate (GFR) and, if left untreated over time, will eventually produce uremic symptoms and retention of sodium and water in the body, leading to both edema and hypertension. Diagnosis
The diagnostic approach to nephritic syndrome includes evaluating the patient for any suspected underlying pathology that could cause a nephritic syndrome. Physical examination
If the person in the office is being examined by a physician, some physical exam findings consistent with nephritic syndrome include the following:

Edema - This could present as generalized edema (anasarca) or specific swelling of the hands, feet, and/or face.
Other signs of fluid overload - Diffuse rales (crackles) may be heard at bilateral lung bases or diffusely in all lung fields on auscultation with a stethoscope. Jugular venous distention (JVD) may also be appreciated when visualizing the veins of the neck on physical exam. Elevated blood pressure - Measured at least two separate times with at least two minutes between measurements using a sphygmomanometer or equivalent method. Abnormal heart sounds - If the underlying cause is cardiac in nature (such as infective endocarditis), then you may appreciate abnormal heart sounds during auscultation of the heart. Laboratory testing
If the physician is suspicious of a possible nephritic syndrome, then he/she may order some common lab tests including:

Serum electrolytes - The kidney is one of the main regulators of electrolytes in the human body and measuring the different electrolyte levels using either a basic metabolic panel (BMP) or comprehensive metabolic panel (CMP) can be a useful indicator of the underlying pathology. Serum creatinine - Also measured using a BMP or CMP, creatinine is one of the most important indicators of current kidney function and is used to calculate the glomerular filtration rate (GFR). An elevated creatinine level is considered abnormal and may indicate decreased kidney function. Blood urea nitrogen (BUN) - Also measured using a BMP or CMP, blood urea nitrogen is an indicator of how much nitrogen is in the blood at the time of the phlebotomy.