Albumin is one of the most important proteins in your body. It is made by your liver and travels through your bloodstream, carrying nutrients, hormones, and other substances to where they need to go. In this article, we explain what albumin does, what affects its levels, and when you should talk to your family doctor about getting tested.
What Is Albumin?
Albumin is a type of protein that dissolves easily in water. It is found in your blood, in egg whites, and in other body fluids. Your liver produces almost all of the albumin in your body.
This protein makes up roughly half of all the protein in your blood plasma. It plays a key role in keeping your blood chemistry balanced and your body working properly. Without enough albumin, many of your body’s systems begin to struggle.
Albumin is also what scientists call a “carrier protein.” Think of it like a delivery vehicle. It picks up important substances — such as calcium, thyroid hormones, and certain medications — and carries them safely through your bloodstream to the organs and tissues that need them.
What Does Albumin Do in Your Body?
Albumin performs several vital jobs every day. Understanding these functions helps explain why low or high levels can signal a health problem worth addressing.
Maintains Fluid Balance
One of albumin’s most important jobs is controlling fluid balance. It keeps fluid inside your blood vessels rather than letting it leak into surrounding tissues. When albumin levels drop, fluid can build up in places like your legs, ankles, or abdomen — a condition called oedema.
This fluid balance function is known as maintaining “oncotic pressure.” In simple terms, albumin acts like a sponge that holds fluid in the right place. Without enough of it, swelling and fluid accumulation become a real problem.
Transports Nutrients and Hormones
Albumin carries essential substances through your blood. These include fatty acids, vitamins, calcium, copper, and zinc. It also carries certain medications, which means albumin levels can even affect how well some drugs work in your body.
For example, thyroid hormones rely on albumin for transport. If your albumin is low, your hormone levels may appear abnormal on a blood test, even if your thyroid itself is healthy. This is one reason doctors look at the full picture when reviewing your results.
Supports Tissue Repair
Albumin also contributes to tissue repair and growth. It provides amino acids — the building blocks your body uses to rebuild damaged tissue. This is especially important during recovery from illness, surgery, or injury.
Furthermore, albumin has mild antioxidant properties. It helps protect your cells from damage caused by harmful molecules. This adds another layer to its already important role in keeping you healthy.
The Albumin Blood Test: What to Expect
Your doctor may order an albumin blood test as part of a routine check-up or to investigate a specific health concern. In Canada, this test is typically covered under provincial health plans when ordered by a physician.
The test is simple and quick. A healthcare provider draws a small sample of blood from a vein in your arm. The sample is then sent to a lab for analysis. Results are usually available within a day or two.
Normal Albumin Levels
Normal albumin levels in adults generally range from 35 to 50 grams per litre (g/L) of blood. However, reference ranges can vary slightly between labs. Always ask your doctor to explain your specific results in context.
Children and older adults may have slightly different normal ranges. Pregnant women also tend to have lower albumin levels, which is completely normal during pregnancy. Your doctor will factor in your age, sex, and health history when reviewing your numbers.
What Affects Test Results?
Several things can influence your albumin levels on a given day. Dehydration, for instance, can make albumin appear higher than it actually is. Lying down for a long period before the test can make it appear lower. Your doctor will take these factors into account.
In addition, inflammation anywhere in the body can temporarily lower albumin levels. This means a single low result does not automatically indicate a serious problem. Your doctor may order a repeat test or additional bloodwork to get a clearer picture.
What Causes Low Albumin Levels?
Low albumin — a condition called hypoalbuminaemia — can result from several different health issues. It is more common than high albumin and tends to get more clinical attention.
According to Mayo Clinic, low albumin is often linked to chronic illness, poor nutrition, or problems with the liver or kidneys. Here are the most common causes:
Liver disease: Because the liver makes albumin, conditions like cirrhosis or hepatitis can reduce production significantly.
Kidney disease: Damaged kidneys may allow albumin to leak into the urine, lowering blood levels. This is called albuminuria or proteinuria.
Malnutrition: Without enough protein in your diet, your liver cannot produce adequate albumin.
Inflammatory conditions: Diseases like Crohn’s disease, lupus, or rheumatoid arthritis can suppress albumin production.
Thyroid disorders: An overactive thyroid (hyperthyroidism) can sometimes reduce albumin levels.
Burns or major injury: Severe burns cause rapid protein loss, leading to a sharp drop in albumin.
Symptoms of Low Albumin
Low albumin does not always cause obvious symptoms on its own. However, when levels drop significantly, you may notice swelling in your legs, ankles, or feet. Some people also experience fatigue, weakness, or a general feeling of being unwell.
In more serious cases, fluid can accumulate in the abdomen — a condition known as ascites. This often signals advanced liver disease. If you notice unusual swelling or persistent fatigue, it is worth speaking with your family doctor.
What Causes High Albumin Levels?
High albumin — called hyperalbuminaemia — is less common but also worth understanding. The most frequent cause is simple dehydration. When your body lacks water, the concentration of proteins in your blood increases.
Other possible causes of high albumin include:
Severe dehydration from vomiting, diarrhoea, or excessive sweating
A high-protein diet combined with dehydration
Certain rare conditions affecting protein metabolism
In most cases, drinking more fluids and addressing the underlying cause brings albumin levels back to normal. However, always follow up with your doctor to rule out anything more serious.
Albumin and Kidney Health
One specific area where albumin gets a lot of attention is kidney health. Healthy kidneys filter waste from your blood but keep large molecules — like albumin — inside your body. When kidneys are damaged, albumin can slip through the filters and appear in your urine.
This is why doctors often test for albumin in urine as an early warning sign of kidney disease. Health Canada recognises chronic kidney disease as a significant public health concern. Catching it early through urine albumin testing can help slow its progression.
The urine albumin-to-creatinine ratio (ACR) is a common test used to screen for kidney damage. If you have diabetes or high blood pressure — both major risk factors for kidney disease — your doctor may order this test regularly as part of your ongoing care.
Albumin and Diabetes
People living with diabetes face a higher risk of kidney damage over time. As a result, Canadian diabetes care guidelines recommend regular urine albumin testing for anyone with Type 1 or Type 2 diabetes. Catching small amounts of albumin in the urine early — called microalbuminuria — allows doctors to act before serious kidney damage occurs.
Furthermore, managing blood sugar, blood pressure, and lifestyle factors can significantly reduce the risk of kidney complications. Talk to your family doctor or diabetes care team about how often you should be tested.
When to See a Doctor
You should speak with your family doctor if you notice any of the following:
Unexplained swelling in your legs, ankles, feet, or abdomen
Persistent fatigue or weakness without a clear cause
Foamy or frothy urine, which can indicate protein loss through the kidneys
Yellowing of the skin or eyes (jaundice), which may suggest liver problems
Unintended weight loss or poor appetite over several weeks
If you do not have a family doctor, a walk-in clinic can be a good first step. A doctor there can order a basic blood panel that includes albumin testing. Most provincial health plans in Canada cover these routine blood tests when ordered by a healthcare provider.
Do not wait if your symptoms are severe or getting worse quickly. Emergency departments are available across Canada if you need urgent care. As always, consult your doctor before drawing any conclusions from your own test results — they are best placed to interpret your numbers in the context of your full health history.
Frequently Asked Questions About Albumin
What does it mean if my albumin is low?
Low albumin can indicate a problem with your liver, kidneys, or nutritional intake. It can also result from chronic inflammation or serious illness. Your doctor will review your full health history to determine the cause and recommend next steps.
Is an albumin blood test covered in Canada?
Yes, in most provinces, an albumin blood test is covered under your provincial health plan when ordered by a doctor. You can ask your family doctor or visit a walk-in clinic to request this test if you have concerns.
What foods help increase albumin levels?
Eating protein-rich foods can help support healthy albumin levels. Good sources include eggs, fish, chicken, legumes, and dairy products. However, if your albumin is low due to a medical condition, dietary changes alone may not be enough — always speak with your doctor first.
What is the difference between albumin in blood and albumin in urine?
Blood albumin measures the amount of this protein circulating in your bloodstream, which reflects liver function and overall nutrition. Urine albumin measures how much is leaking through your kidneys, which is an early sign of kidney damage. Both tests serve different but complementary purposes.
Can dehydration affect my albumin test results?
Yes, dehydration can make albumin levels appear higher than they actually are because your blood becomes more concentrated. It is a good idea to be well-hydrated before any blood test. Your doctor will consider this when interpreting your albumin results.
Is low albumin dangerous?
Significantly low albumin can be a sign of a serious underlying condition and should not be ignored. It is associated with increased health risks, particularly in people who are hospitalised or managing chronic illness. According to Healthline, treating the root cause is the most effective way to restore healthy albumin levels.
Key Takeaways
Albumin is a vital protein made by your liver that keeps your blood chemistry balanced.
It carries nutrients, hormones, and medications through your bloodstream to where they are needed.
Normal albumin levels in adults range from 35 to 50 g/L of blood.
Low albumin can signal liver disease, kidney problems, or poor nutrition.
High albumin is most often caused by dehydration.
Urine albumin testing is an important early screening tool for kidney disease, especially in people with diabetes or high blood pressure.
If you notice swelling, persistent fatigue, or foamy urine, speak with your family doctor or visit a walk-in clinic.
Most albumin blood tests are covered by provincial health plans in Canada when ordered by a healthcare provider.
Always consult your doctor to interpret your test results — they are best placed to guide your care.
