Total Bilirubin

Total bilirubin is a measure of all bilirubin in your blood, a yellow pigment made when your body recycles old red blood cells. The liver “processes” bilirubin so it can be excreted in bile. Total bilirubin therefore reflects how well red cells are being turned over, how smoothly the liver is handling bile flow, and whether bilirubin is building up in the bloodstream.

Bilirubin acts as an antioxidant in small amounts, but higher blood levels can signal problems with bile flow or liver processing, or faster-than-usual red cell breakdown. Tracking total bilirubin over time alongside related markers like ALT, AST and alkaline phosphatase helps separate benign patterns from those that deserve attention sooner.

Lifestyle shifts can support a healthy liver and make your bilirubin trend line steadier:

• If you smoke, stopping nudges bilirubin upward into a more favourable range. In a randomized trial of smokers, people who quit saw ~0.06 mg/dL (≈1.0 µmol/L) higher indirect bilirubin versus non-quitters, a change linked to lower cardiometabolic risk. That rise is small but meaningful for antioxidant capacity.
  

• Train regularly, with enough “dose” over time. In a 6-month trial, only the highest exercise volume group increased total bilirubin, by ~0.044 mg/dL (≈0.75 µmol/L), with the biggest gains in those with insulin resistance at baseline. Consistent aerobic training plus some higher-intensity days appears to shift bilirubin modestly in a favourable direction.
  

• Care for your liver daily. Keep alcohol moderate, maintain a healthy waistline, and prioritise sleep and nutrient-dense meals. These habits support bile flow and the enzymes that process bilirubin, stabilising your results over months and years.
  

• Note short-term context. Intercurrent illness, crash dieting, very intense bouts of exercise, or dehydration can temporarily change bilirubin. Logging these around your test helps you interpret one-off bumps versus real trends over time.

• Optimal: 5–17 µmol/L

• Borderline high: 18–34 µmol/L

• High: >34 µmol/L

• Low: <5 µmol/L, usually not clinically important on its own

1. MedlinePlus. Bilirubin blood test. U.S. National Library of Medicine, 2025. Available from: https://medlineplus.gov/ency/article/003479.htm

2. Royal College of Pathologists of Australasia. Bilirubin (RCPA Manual), 2024. Available from: https://www.rcpa.edu.au/Manuals/RCPA-Manual/Pathology-Tests/B/Bilirubin

3. StatPearls. Gilbert Syndrome. NCBI Bookshelf, 2024. Available from: https://www.ncbi.nlm.nih.gov/books/NBK470200/

4. O’Malley SS, et al. Smoking cessation is followed by increases in serum bilirubin. Nicotine & Tobacco Research, 2014. Available from: https://pubmed.ncbi.nlm.nih.gov/24812024/

5. Swift DL, et al. Effect of different doses of aerobic exercise training on total bilirubin levels. Medicine & Science in Sports & Exercise, 2012. Available from: https://pubmed.ncbi.nlm.nih.gov/21900842/