Summarize:

Edema, the swelling in various parts of the body due to excess water accumulation, is the initial symptom of nephrotic syndrome in about 95% of the patients.  Common places for this extra fluid include the face (around the eyes and particularly in the morning after lying in bed all night), the legs (particularly the lower legs and after being upright during the day), within the abdominal cavity (where there is lots of space for it to accumulate), and in the genitalia. It may be mild or sufficiently severe to cause a great deal of discomfort. As blood levels of proteins decrease, a portion of water contained in the blood moves out of the blood vessel and into surrounding tissue. Elevated levels of LDL cholesterol and triglycerides result from abnormal processing of the cholesterol and triglyceride precursors in the nephrotic syndrome. Relatedly, obesity and/or weight gain is a common side effect, too.  In severe and prolonged nephrotic syndrome these levels may be extremely high, raising concerns about long-term heart disease and cardiovascular risk in general. Increased risks of serious bacterial infections are seen in people with nephrotic syndrome. There are several changes that occur in the efficiency of our immune systems that principally result from losing certain proteins in the urine: sepsis (bacteria in the blood), peritonitis (bacterial infection in the abdomen), and cellulitis (bacterial infection of the skin) are the most common.  The most frequently seen bacterial organisms causing these infections are Streptococcus pneumoniae (pneumococcus) and bowel bacteria such as Escherichia coli. Disturbances of blood clotting can lead to thrombosis (blood clots forming within body blood vessels) of major blood vessels. This is, however, more common in adult forms of nephrotic syndrome.  It is principally the result of imbalances of normal blood clotting regulation, with increases of factors that enhance blood clotting accompanied by urinary losses of substances that inhibit blood clotting. Acute kidney failure associated with the nephrotic syndrome is uncommon, particularly in the idiopathic nephrotic syndrome of childhood. When it does occur, it is usually the result of dehydration in the blood compartment of the body.  Both the very low blood protein levels leading to loss of blood volume, and fluid losses from acute illnesses with dehydration can combine and lead to poor blood flow to the kidney. This is often reversible with prompt treatment of the underlying problem. Unfortunately, prolonged steroid therapy has its own complications. Each case is different, and your child may experience only some of these symptoms. Knowing that, here are the most common side effects of prolonged therapy:   Weight gain, increased appetite, and obesity "Cushingoid” facial changes (rounded face sometimes called a "moon" face) Infection Growth delay Cataracts High blood pressure High blood sugars Weakening of the bones (osteopenia) Skin stretch marks Serious side effects may not be experienced by a child whose SSNS relapses are infrequent and require only modest does of steroids.
Expect swelling. Keep an eye on your child's cholesterol. Know that you're up against infection. Know that thrombosis is a complication. Monitor the kidneys. Know the complications of therapy, too.