Introduction
Bilirubin is the yellow pigment, bile, released during the breakdown of red blood cells. A normal bilirubin level in adults indicates good overall health, but an abnormally high level affects liver health because it is unable to process or break down bilirubin and may block the bile duct and give rise to certain blood disorders.
Let's discuss in this blog normal, high, and critical bilirubin values, their causes, symptoms, and when medical attention is required.
What Is Bilirubin?
Bilirubin is a yellow pigment produced as a byproduct of the degradation of Red Blood cells. When hemoglobin in the RBC breaks down, it passes into the liver, where it is processed and excreted through bile in the intestine.
What Are the Different Types of Bilirubin
Direct Bilirubin (conjugated): It is a water-soluble form processed by the liver; higher level indicates liver damage, blockage in the bile duct, and it can be directly measured through a blood test and ranges from 0-0.3mg/dlIndirect Bilirubin (unconjugated): This is a fat-soluble product from the breakdown of RBC that circulates in the blood before being processed by the liver. High levels of it indicate hemolysis(RBC destruction) or an inherited condition like Gilbert syndrome (affects bilirubin metabolism), calculated by subtracting (total bilirubin - direct bilirubin)
Total Bilirubin: Measures direct + indirect bilirubin, representing the overall bilirubin levels in the blood.
Delta bilirubin (biloprotein): Covalently bound to albumin, it appears when the level of conjugated bilirubin is very high due to impaired hepatic excretion in patients with hepatobiliary disease.
Bilirubin Level in Adults (Normal Range)
Below is the normal bilirubin level summarized in tabular form for individuals above 18
|
Bilirubin Type |
Normal Range (Adults 18+) |
|
Total Bilirubin |
0.1 – 1.2 mg/dL |
|
Direct (Conjugated) Bilirubin |
0.0 – 0.3 mg/dL |
|
Indirect (Unconjugated) Bilirubin |
0.2-0.8 mg/dL |
Key points
- The value may vary depending on the lab conditions. Consult with your doctor accordingly.
- Total bilirubin includes both direct (conjugated) and indirect (unconjugated) bilirubin.
- Direct bilirubin shows how well the liver processes and excretes bilirubin into bile.
- A high indirect bilirubin level indicates increased red blood cell breakdown.
- Mild fluctuations in results can be observed due to fasting, dehydration, and certain medications.
High Bilirubin Levels in Adults
|
Bilirubin Level |
Range (mg/dL) |
What It Means |
|
Mild Elevation |
1.2 – 2.9 |
Indicates an inherited condition, Gilbert’s syndrome, or early liver stress |
|
Visible Jaundice |
More than 2.6 – 3.0 |
May suggest jaundice (Yellowing of the skin and eyes) |
|
High Level |
Above 3.0 |
Key points
- Slight increases are often mild and temporary, depending upon the health condition of an individual.
- Jaundice usually appears when bilirubin comes in the range of 2.6 to ~3 mg/dL.
- High levels require medical attention and further tests.
Critical Bilirubin Level in Adults
|
Risk Level |
Bilirubin Level (mg/dL) |
|
High Risk |
5 mg/dL and above |
|
Dangerous |
10 mg/dL and above |
|
Severe Acute Liver Failure |
Key notes
- A level above 5 mg/dL suggests acute liver injury or severe bile duct obstruction.
- 10 mg/dL and above indicates severe liver disease, major biliary obstruction, or suggests hemolysis (breakdown of hemoglobin)
- More than 18 mg/dl may indicate a risk of death and requires immediate medical care.
What Are the Causes of High Levels of Bilirubin (Hyperbilirubinemia)
Increased Red Blood Cell Breakdown: Some of the conditions, including hemolytic anemia, blood disorders, or transfusion reactions, increase bilirubin production.Liver Disease or Damage: Hepatitis, cirrhosis, fatty liver disease, or liver cancer reduces the liver’s ability to process bilirubin.
Bile Duct Blockage: This can happen due to conditions like gallstones (due to high cholesterol and bilirubin hardening the gallbladder), pancreatitis, or tumors that block bile flow and prevent bilirubin excretion.
Intrahepatic Cholestasis of Pregnancy: Occurs during the last trimester of pregnancy, where bile flow from the liver slows or stops, affecting bilirubin processing and leading to higher bilirubin levels in the blood.
Newborn Jaundice: Occurs when a newborn’s immature liver cannot efficiently handle rapid red blood cell turnover as their liver are not properly developed. This condition can resolve on its own within a week but requires attention if persist for longer.
Genetic Factors: Some of the inherited genetic isorders such as Gilbert’s syndrome or Crigler–Najjar syndrome, can affect normal bilirubin metabolism.
High Bilirubin Level Symptoms
- Yellowing of the skin and eyes(jaundice).
- Dark colour Urine
- Pale Light-colored, Stools or grayish stools.
- Itchy Skin (: Persistent itching (Pruritus)
- Fatigue & Weakness
- Swelling or upper right Abdominal pain.
- Nausea & Vomiting
- Fever & Chills due to underlying infection(viral hepatitis or a bile duct infection)
Symptoms in Newborns (Infant Jaundice)
- Yellowing of the skin and eyes.
- Fussiness.
- Poor feeding.
- Lethargy or unusual sleepiness.
Immediate medical evaluation is required when bilirubin levels reach critical value.
How to Diagnose a High Bilirubin Level in Blood
The diagnosis of high bilirubin levels in blood can be detected and involves a combination of medical history review, physical examination, and specific diagnostic tests.
Blood Tests
The most direct way to diagnose and monitor bilirubin levels is through blood analysis.
- Total Bilirubin: The combined level of both conjugated (direct) and unconjugated (indirect) bilirubin.
- Direct Bilirubin (Conjugated): Measures the form that has been processed by the liver.
- Indirect Bilirubin (Unconjugated): Calculated by subtracting direct bilirubin from total bilirubin.
- Alanine aminotransferase (ALT) Aspartate aminotransferase (AST)
- Alkaline phosphatase (ALP)
- Albumin and Total Protein
- Prothrombin time (PT/INR)
Imaging Tests
If the Bilirubin levels are abnormally high several imaging test can be done to assess the condition these include
Abdominal Ultrasound: Diagnoses the complete abdomen, including the gallbladder and bile ducts, helping to detect gallstones, tumors, or dilation of the bile ducts.Computed Tomography (CT) Scan or Magnetic Resonance Imaging (MRI): Provides detailed images of the liver and surrounding structures to look for masses, tumours cirrhosis, or any internal blockages.
Magnetic Resonance Cholangiopancreatography (MRCP): It provides detailed images of the bile ducts, gallbladder, and pancreatic duct, highly effective for detecting blockages.
How to Manage High Bilirubin Levels at Home?
Treatment depends upon the underlying cause. Here are some of the tips that can help you lower the bilirubin level this include:-
Be hydrated: Drinking plenty of water helps your body process and eliminate excess bilirubin efficiently.Eat a well-balanced diet: Include essential protein that supports liver repair, while fruits, vegetables, and whole grains provide antioxidants and fibre that promote liver health.
Limit or avoid alcohol: Alcohol affects the liver which can interfere with bilirubin metabolism. In case you have liver disease, it’s best to avoid alcohol completely.
Manage underlying conditions: Conditions such as hepatitis, cirrhosis, or bile duct disorders should be carefully managed in consultation with your doctor.
Avoid self-medication: Some medicines can put your liver under stress. Consult your doctor before starting new medications