Key Symptoms and Health Effects of Albumin in Urine
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.
The acetic acid and heat test
Sulfosalicylic acid test,
Heller's test, and
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.
Conclusion
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.
FAQs on Albumin in Urine: Meaning, Causes & How to Reduce It
1. What does the presence of albumin in urine indicate?
The presence of albumin in urine, a condition known as albuminuria or proteinuria, is a primary indicator of kidney damage. It suggests that the kidneys' filtering units, the glomeruli, are compromised and are allowing albumin, a large protein, to leak from the blood into the urine. This is often an early sign of chronic kidney disease, commonly associated with conditions like diabetes and high blood pressure.
2. Why is albumin normally absent from urine, and what part of the kidney fails when it appears?
In a healthy individual, albumin is absent from urine because it is a large molecule that cannot pass through the kidney's glomerular filtration barrier. This barrier in the nephron is made of specialized cells, including podocytes, which create fine filtration slits. When diseases like diabetes or hypertension damage this barrier, its pores widen, losing their selective permeability. This allows albumin to leak from the blood into the filtrate, which then becomes part of the urine.
3. What are the primary causes of albuminuria?
The primary causes of persistent albumin in the urine are typically related to chronic conditions that affect the kidneys. The most common causes include:
- Diabetic Nephropathy: High blood sugar levels over time can damage the glomeruli, which is the leading cause of albuminuria.
- Hypertension: High blood pressure can exert force on the delicate blood vessels of the kidneys, leading to damage and leakage.
- Glomerulonephritis: Inflammation of the glomeruli, which can be caused by infections or autoimmune diseases.
- Preeclampsia: A condition during pregnancy characterized by high blood pressure and protein in the urine.
Temporary factors like fever, dehydration, or intense physical exercise can also cause transient albuminuria.
4. What are considered normal and high levels of albumin in urine?
The amount of albumin in urine is typically measured by the urine albumin-to-creatinine ratio (UACR). The levels are generally categorised as:
- Normal: Less than 30 milligrams per gram (mg/g) of creatinine.
- Microalbuminuria: Between 30 and 300 mg/g. This is considered an early sign of kidney disease.
- Macroalbuminuria: Above 300 mg/g. This indicates more significant kidney damage.
5. What does a 'trace' amount of albumin in urine signify, and is it always a problem?
A 'trace' amount of albumin indicates a very small quantity that is barely detectable. While it can be an early warning sign for microalbuminuria, it is not always a cause for alarm. Temporary conditions such as dehydration, high fever, or recent strenuous exercise can cause a transient trace amount. However, if trace albumin is detected consistently over several tests, it warrants further medical investigation to rule out the onset of chronic kidney disease.
6. How is the test for albumin in urine conducted as per the CBSE 2025-26 syllabus context?
In a clinical context relevant to the biology syllabus, the most common method is the Urine Albumin-to-Creatinine Ratio (UACR) test. This involves analysing a spot urine sample. The test measures both albumin and creatinine. Measuring creatinine helps to normalise the albumin level, accounting for variations in urine concentration due to hydration. This provides a more accurate picture of albumin excretion than measuring albumin alone.
7. Why is monitoring for albumin in urine particularly important during pregnancy?
Monitoring for albumin in the urine is crucial during pregnancy because its presence can be a key sign of preeclampsia. Preeclampsia is a serious condition that typically develops after 20 weeks of gestation and is characterized by high blood pressure and organ damage, indicated by proteinuria. Early detection through regular urine tests allows for prompt management to ensure the health and safety of both the mother and the developing fetus.
