Blurred vision
Azotemia (increased plasma Urea and Creatinine)
Oliguria (low urine output <400 ml/day)
Red blood cell casts (seen with urinalysis and microscopy)
Pyuria (white blood cells or pus in the urine)

Causes
Nephritic syndrome is caused by extensive inflammatory damage to the glomerulus capillaries, which is associated with a variety of medical conditions that we will discuss. Furthermore, the cause of this inflammation can be infectious, autoimmune, or thrombotic. The causative conditions can be divided conveniently between age groups as follows, though it is important to note that many of the conditions listed in children/adolescents can also occur in adults with lower frequency, and vice versa:

Children/adolescents
IgA nephropathy (Note: Contrast time of onset with Post-streptococcal Glomerulonephritis) - Most commonly diagnosed in children who recently had an upper respiratory tract infection (URI). Symptoms typically present within 1–2 days of a non-specific URI with severe flank/abdominal pain, gross hematuria (characterized by dark brown or red colored urine), and edema of the hands, feet, and/or face. Post-streptococcal glomerulonephritis (PSGN) - Similar to IgA nephropathy, post-streptococcal glomerulonephritis (PSGN) most often occurs in children who have recently had an upper respiratory infection (URI). In contrast with IgA nephropathy, however, PSGN typically presents 2–3 weeks after recovering from an URI that was caused specifically by a Streptococcus bacteria. The symptoms at onset are very similar to IgA nephropathy and include abdominal pain, hematuria, edema, and oliguria.
The kidney is responsible for excreting nitrogenous substances in the urine, so an elevated BUN usually indicates that the kidney is not functioning appropriately. Urine Analysis (Urinalysis) - After the patient provides a urine specimen, it is sent to the lab for analysis using a variety of methods including urine dipstick testing and microscopic examination. Because the kidney is responsible for making urine, analyzing the urine directly can provide crucial data that can help the physician diagnose nephritic syndrome. Some findings on urinalysis that are consistent with nephritic syndrome include red blood cells (hematuria), red blood cell casts, proteinuria, and possibly white blood cells (pyuria).If nephritic syndrome is identified and diagnosed, then it is important for the physician to determine the underlying cause. To do this, he/she may order any of a large variety of relevant lab tests, some of which are included here:

Blood culture - This is the process where a sample of the patients blood is sent to the microbiology lab to attempt to isolate and grow any bacteria that may be circulating in the blood, in order to identify the pathogen. This is helpful if the physician suspects infection as the underlying cause of the nephritic syndrome. Antinuclear antibody (ANA) titer - ANA is commonly positive in patients who have an underlying autoimmune disease, so this test is useful if the physician suspects an underlying autoimmune disease (refer to the Causes section above for examples) as the cause of the presenting nephritic syndrome.