What Is Nephrotic Syndrome and How Does It Affect the Body?

Nephrotic syndrome is a serious kidney disorder characterized by a group of symptoms that indicate your kidneys are not functioning properly. One of the hallmark signs is massive proteinuria, where excessive amounts of protein leak into the urine—often visible as increased foaming during urination. In clinical tests, this typically shows up as protein levels of (+++) or higher on a urine dipstick test, with a 24-hour urine protein excretion of at least 3.5 grams.

Understanding the Physiological Impact

When large quantities of protein are lost through urine, blood albumin levels drop significantly—usually to 30 g/L or lower—a condition known as hypoalbuminemia. To compensate, the liver increases its production of albumin. However, it also ramps up the synthesis of other substances, including lipoproteins and clotting factors. This overproduction leads to several secondary complications, such as elevated cholesterol, high triglyceride levels, increased low-density lipoprotein (LDL), and a heightened risk of blood clots due to a hypercoagulable state.

Metabolic Consequences of Nephrotic Syndrome

This imbalance in protein and lipid metabolism often results in hyperlipidemia, making patients more vulnerable to cardiovascular diseases. The body's attempt to restore equilibrium inadvertently worsens the situation, contributing to long-term vascular damage and increasing the likelihood of stroke or heart attack if left unmanaged.

Types and Causes of Nephrotic Syndrome

Nephrotic syndrome is relatively common in nephrology but can be challenging to treat effectively. It falls into two main categories: primary (idiopathic) and secondary. Primary nephrotic syndrome originates directly from intrinsic kidney disease, most commonly due to glomerular damage such as minimal change disease, focal segmental glomerulosclerosis (FSGS), or membranous nephropathy.

Identifying Secondary Causes

Secondary nephrotic syndrome arises as a complication of systemic conditions. Common underlying causes include diabetic nephropathy, lupus nephritis, hepatitis B-associated glomerulonephritis, and cancer-related kidney disorders. Before diagnosing primary nephrotic syndrome, physicians must carefully rule out these secondary triggers through comprehensive testing and medical history evaluation.

The Role of Kidney Biopsy in Diagnosis and Treatment

For cases suspected to be primary nephrotic syndrome, a renal biopsy is often essential. This procedure allows doctors to examine kidney tissue under a microscope and identify the specific pathological type. Knowing the exact pathology helps tailor treatment plans, predict disease progression, and estimate long-term outcomes. Treatments may include corticosteroids, immunosuppressants, ACE inhibitors, or lifestyle modifications depending on the diagnosis.

Early detection and personalized management are key to improving quality of life and preventing irreversible kidney damage. Patients experiencing persistent swelling (especially around the eyes and legs), fatigue, or frothy urine should seek prompt medical evaluation. With proper care, many individuals with nephrotic syndrome can achieve remission and maintain stable kidney function over time.