Albumin
Serum Albumin
What this test measures
Albumin is a protein made by your liver. It helps keep fluid in your blood vessels and carries important substances around your body. Low levels can indicate liver or kidney problems.
Understanding the numbers
Typical range: 35-50 g/L
Albumin can be affected by nutrition, inflammation, and how well your liver and kidneys work.
- Severely low: 15–25 g/L
- Low: 25–35 g/L
- Normal: 35–50 g/L
- High: 50–60 g/L
Key numbers
- 25 g/L — Severely low — risk of fluid shift / swelling
- 35 g/L — Lower limit of normal
- 30 g/L — Prognostic threshold in many chronic conditions
Typical UK reference range. Albumin is a negative acute-phase protein — it falls with inflammation, infection, nephrotic syndrome and chronic liver disease. Low albumin is used as a prognostic marker in heart failure, cancer and frailty.
Ranges can vary slightly between laboratories — your report may show slightly different numbers. This page does not read or interpret your result; your GP looks at it alongside your history and other tests.
What a higher-than-normal result can mean
- High albumin is uncommon
- Usually caused by dehydration
- Drinking more fluids may help
- Your GP will advise if any action is needed
Questions you could ask your GP
- What might be causing my low albumin?
- Do I need tests to check my liver or kidneys?
- Should I make any changes to my diet?
- Is this related to any other health conditions I have?
Example stories
These are made-up examples to show how results are talked about in real appointments. They are not real patients.
Low albumin — frail and malnourished
Henry had lost 6 kg over three months after his wife's death. His albumin was 28 g/L and his grip strength was weak.
What the GP said: “Your low albumin reflects that you haven't been eating well. Frailty and poor nutrition lower it. We'll refer to a dietitian and I'll ask the community team to see you about meals and wellbeing.”
What happened next: With community support and oral nutritional drinks, Henry regained 3 kg and his albumin came back to 35 over four months.
Low albumin in older adults is often about malnutrition and frailty — treating the cause (nutrition, social circumstances, mood) is more effective than any medicine.
Nephrotic syndrome — protein lost in urine
Nabila had puffy eyes, swollen ankles and frothy urine. Albumin 22, urine protein very high (urine ACR >250 mg/mmol).
What the GP said: “Your kidneys are leaking protein — this is nephrotic syndrome. I'm referring you urgently to the kidney team for a biopsy and treatment.”
What happened next: Biopsy showed minimal change disease; steroids brought her albumin back to 38 over three months.
Low albumin with protein in the urine and swelling points to nephrotic syndrome — the kidneys are losing protein. This is urgent and needs specialist care to find the cause and start treatment.
Cirrhosis — chronic low albumin
Cormac had known cirrhosis. Albumin 26, bilirubin 38, INR 1.5 — features of reduced liver synthesis.
What the GP said: “Your liver is struggling to make albumin and clotting factors. We'll keep you on the transplant assessment list and manage your ascites carefully — that's the fluid build-up in your tummy.”
What happened next: Cormac remained on the list, was reviewed every three months and received a transplant 18 months later.
Albumin is a key marker of the liver's synthetic function. In cirrhosis, falling albumin alongside rising bilirubin and INR indicates worsening liver function — not just an isolated number.
Low albumin during severe infection
Reena was admitted with severe pneumonia and sepsis. Albumin dropped from 38 pre-admission to 24 on day 2 of hospital treatment.
What the GP said: “Severe infection pulls albumin out of the blood into tissues — that drop is expected. As you recover the albumin will climb back up. No specific treatment is needed for the number itself.”
What happened next: Reena recovered from the pneumonia; her albumin was back to 36 at the 6-week follow-up.
Albumin is a negative acute-phase protein — it drops sharply during severe infection and inflammation and comes back as the person recovers. You don't treat the number in isolation.
Before you act on anything here
This page is general information, written to help you understand — it is not personal medical advice and it cannot tell you what is right for you. Talk to your own GP, pharmacist or nurse about your own health.
- Need help now but it's not an emergency? Call NHS 111 or use 111.nhs.uk.
- Emergency? Call 999 or go to A&E.