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Albumin in Urine

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Albumin in Urine: An Introduction

Albumin is a protein produced in the liver from dietary amino acids. Albumin protein passes through the filtrate, causing Glomerular Proteinuria. Due to an increase in permeability of the glomerular capillary wall caused by injury to one or more components of the glomerular filtration barrier, high molecular weight proteins, primarily albumin, escape into the urine area. In the following sections, we will discuss what albumin in urine trace means during pregnancy in women and otherwise in men and women, its symptoms, and ways to reduce it.

What is Albumin in Urine?

Albumin is a protein found in plasma that is responsible for the blood's osmotic characteristics. Albumin is a plasma component that keeps and adds volume to the blood by pulling fluid from interstitial tissues to maintain a balance. Doctors employ this factor to raise blood volume in shock patients and prolong their lives. In blood plasma, albumin is a transport protein. In the following section, we will discuss what albumin in urine means for our body.

The blood filters through glomerulus and filtrates into renal tubules. If albumin filters through glomerulus after filtration it can damage the kidney and lead to albuminuria and proteinuria. Proteinuria is the presence of excessively large amounts of protein in the urine, mainly albumin. Proteins are massive molecules that the kidney does not ordinarily filter, but those that do are reabsorbed. The presence of these in the urine can be caused by a variety of acute and chronic conditions.

Healthy people excrete less than 250 mg of protein each day. Excessive proteinuria is frequently an indication of renal disease or renal problems induced by other diseases like hypertension or heart failure.

Albumin in Urine Test

  • Albumin has four qualitative tests.

  1. The acetic acid and heat test

  2. Sulfosalicylic acid test,

  3. Heller's test, and

  4. Robert's test.

  • The Kwilecki Modification of Esbach's Method and the Kingsbury and Clark Method are two quantitative tests for albumin. Picric acid and citric acid are Esbach's reagents. Chemically, the Kingsbury and Clark Method contains 3% sulfosalicylic acid.

  • A regular urine dipstick will not identify microalbumin. Only when macro albuminuria (> 300 mg/day) is present does the dipstick turn positive.

  • Albumin/creatinine ratio (ACR) is the most used quantitative assay for microalbumin.

  • Urine albumin and urine creatinine are measured in a spot (untimed) urine sample delivered to the lab (ideally done on first-morning urine for reproducibility, but in practice is often sent at any time)

  • Albuminuria can be temporary (e.g., due to a fever or strenuous exercise) to be regarded as relevant, the screen must be positive over a 3-6 month period.

Albumin in Urine Symptoms

Albuminuria is the most common symptom of glomerular disease. Glomerular proteinuria is further subdivided into the following categories: microalbuminuria and macroalbuminuria. It can cause "Nephrotic Syndrome," which is characterised by low serum albumin, hyperlipidaemia, and severe oedema.

The presence of minute levels of albumin in the urine is the first sign of diabetic kidney damage. Even among non-diabetics, it is a strong predictor of cardiovascular disease. It could be a symptom of endothelial dysfunction in general. Microalbuminuria is achieved through the development of macro albuminuria (sometimes known as "overt nephropathy"), with a subsequent steady reduction in GFR leading to advanced Chronic Kidney Disease (CKD).

Albumin in Urine During Pregnancy

Proteinuria, or the presence of a large amount of protein in one's urine, is an indication of renal disease. When it's combined with high blood pressure after 20 weeks of pregnancy, it's a symptom of preeclampsia. A daily amount of more than 300 mg is considered excessive during pregnancy.

Preeclampsia is a pregnancy-related illness characterised by elevated blood pressure, proteinuria (protein loss in the urine), and oedema. It's a pregnancy-specific condition in which a previously normotensive woman develops hypertension and proteinuria (protein in urine at or greater than 40 mg/dl concentration) after 20 weeks of pregnancy.

Albumin in Urine Normal Range

The glomerulus filters albumin, but the proximal tubule absorbs most of it.

  • In normal urine, albumin levels are less than 1 mg/dl. Albumin is measured in EU (equivalent units) before being converted to grams.

  • A healthy kidney is excellent at retaining protein: 150mg per day is considered normal.

  • Massive amounts of protein can be spilled by a diseased kidney: Abnormal: >150mg/20+ grams per day.

  • Microalbuminuria (30-300 mg/per day) and macro-albuminuria (>300 mg/day).

  • A healthy person excretes 150mg of urine protein every day. Normal urine contains 10-30 mg of albumin.

How to Reduce Albumin in Urine

Albumin levels can be lowered by taking the right medications after consulting with a doctor. The medication aids in the reduction of blood pressure. The filtration rate of urine is increased by elevated blood pressure. Albumin is a protein that flows with the filtrate and is not absorbed by the renal tubules. As a result, lowering excessive blood pressure is essential. It can be decreased by using blood pressure medications known as ACE inhibitors or ARBs.


Albumin is a protein in plasma and filtered through the glomerulus. Kidneys stop albumin from leaving the blood and entering the urine. A damaged kidney causes some albumin to pass into the urine. Albuminuria is a kidney disease symptom that denotes an abundance of albumin in the urine. The albumin in urine creates many diseases and problems. The article provides all the necessary information about the albumin in urine and helps to understand the symptoms and effects of albumin in urine above the normal range.

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FAQs on Albumin in Urine

1. What are the causes of the presence of albumin in urine?

Albumin is a protein that is present in the blood. Blood filters through the kidney and waste materials in the blood are passed into renal tubules via filtration in the glomerulus. The damage in the glomerulus causes the pass of albumin protein into the filtrate and then urine. Sometimes overproduction of albumin protein increases glomerular filtration that increases filtered load if filtrate load is more than proximal tubule reabsorption capacity decreases. The absorption of albumin protein through renal tubules cannot take place and increase excretion with albumin. 

2. Why is albumin not excreted in the urine in normal conditions?

The molecular weight of the protein is more. The glomerulus has podocytes and some other barriers that help in preventing the flow of these proteins into the renal tubules. Some kidney diseases, diabetes, and high blood pressure cause some damage to the glomerulus. The podocytes are small pores present in the basal layer of the glomerulus and help in filtration and pass the proteins and substances that are smaller than their pore size. The damage of the basal layer also damages the podocytes and large-sized proteins move inside the filtrate. So in normal conditions, the albumin cannot filter through the glomerulus. 

3. Why do the levels of serum albumin decline with age?

As people age, their levels of nutrition and energy decline. We are aware that albumin is a protein found in blood. Malnutrition and reduced liver activity are the main causes of the reduction in albumin protein levels. Malnutrition results in reduced protein intake, poorer protein absorption, and increased gastrointestinal protein loss. Due to edentation, many elderly people avoid meat. The elderly want to consume soft foods unbothered. As people get older, their livers produce fewer proteins and their functions decline.

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