The HbA1c test measures the average blood glucose levels over the past two to three months. It reflects how much glucose is attached to haemoglobin in red blood cells. This test is commonly used to diagnose and monitor diabetes.​

When Low

A low HbA1c level may indicate episodes of hypoglycaemia (low blood sugar), which can cause symptoms like dizziness, sweating, and confusion. It may be a sign of overly aggressive diabetes treatment or other health conditions affecting blood sugar levels.​

When High

A high HbA1c level suggests poor blood sugar control, indicating a higher risk of diabetes-related complications such as nerve damage, kidney disease, and cardiovascular issues.

Iron is a vital mineral necessary for producing haemoglobin, the protein in red blood cells that carries oxygen. Adequate iron levels are essential for energy production and overall health.​

When Low:

Iron deficiency can lead to anaemia, causing symptoms like fatigue, weakness, and shortness of breath. Common causes include poor dietary intake, blood loss, or increased demand during pregnancy.​

When High:

Excessive iron levels may result from conditions like haemochromatosis, leading to joint pain, fatigue, and organ damage if untreated .​

TIBC measures the blood's capacity to bind iron with transferrin, reflecting iron transport availability.​

When Low:

Low TIBC can indicate chronic diseases, malnutrition, or iron overload conditions like haemochromatosis.​

When High:

Elevated TIBC is often seen in iron deficiency anaemia, where the body increases transferrin production to maximize iron transport .​

UIBC measures the reserve capacity of transferrin to bind more iron, helping assess iron metabolism.​

When Low:

Low UIBC suggests high iron saturation, possibly due to iron overload disorders.​

When High:

High UIBC indicates low iron levels, as seen in iron deficiency anaemia, reflecting increased transferrin availability.​

Transferrin saturation calculates the percentage of transferrin bound with iron, providing insight into iron availability.​

When Low:

Low transferrin saturation is indicative of iron deficiency, leading to anaemia and associated symptoms.​

When High:

High transferrin saturation may point to iron overload conditions, necessitating further evaluation and management.​

Triglycerides are a type of fat found in the blood, used for energy. After eating, the body converts excess calories into triglycerides, storing them in fat cells.​

When Low:

Low triglyceride levels are usually not a concern and may indicate a healthy metabolism. However, extremely low levels can be associated with malnutrition or certain medical conditions.​

When High:

High triglyceride levels can increase the risk of heart disease and pancreatitis. They are often associated with obesity, uncontrolled diabetes, and excessive alcohol consumption. Lifestyle modifications, including diet and exercise, are key to lowering triglyceride levels.​

Total protein measures the combined amount of albumin and globulin in the blood. Proteins are essential for various bodily functions, including immune responses and maintaining fluid balance.​

When Low:

Low total protein levels may indicate liver or kidney disease, or issues with protein digestion or absorption. Symptoms can include swelling, fatigue, and infections.

When High:

High total protein levels could be due to dehydration or certain types of cancer, such as multiple myeloma. Further tests are needed to determine the specific cause.

Albumin is the most abundant protein in the blood plasma, produced by the liver. It maintains oncotic pressure and transports hormones, vitamins, and drugs.​

When Low:

Low albumin levels can result from liver disease, kidney disease, or malnutrition. Symptoms may include swelling, fatigue, and muscle weakness.​

When High:

High albumin levels are rare and often indicate dehydration. Rehydration typically normalizes levels.​

Globulins are a group of proteins involved in liver function, blood clotting, and fighting infections.​

When Low:

Low globulin levels may suggest liver or kidney disease, or immune deficiencies. Symptoms can include increased susceptibility to infections.​

When High:

High globulin levels can be associated with chronic infections, inflammatory diseases, or certain cancers. Further testing is necessary to determine the cause.​

ALP is an enzyme found throughout the body, but mainly in the liver, bones, kidneys, and digestive system. It plays a role in breaking down proteins and is especially important for bone health.

When Low:

Low ALP levels might be linked to conditions such as malnutrition, protein deficiency, or certain inherited disorders like hypophosphatasia, a rare bone disease. Symptoms might include bone pain, muscle weakness, and fatigue.

When High:

High ALP levels can suggest liver disease, bile duct obstruction, or bone disorders such as Paget’s disease or bone cancers. Symptoms may include bone pain, fragile bones (increased risk of fractures), itching, or signs of jaundice if the liver is affected.

Bilirubin is a yellow substance produced during the normal breakdown of red blood cells. It is processed by the liver and excreted in bile. Bilirubin levels help assess liver function and can indicate problems with red blood cell breakdown.

When Low:

Low bilirubin is generally not a concern and doesn’t usually cause symptoms. However, abnormally low bilirubin could sometimes hint at increased oxidative stress or an overactive liver.

When High:

High bilirubin levels can lead to jaundice, where the skin and eyes turn yellow. It may indicate liver diseases (like hepatitis or cirrhosis), gallstones, or hemolytic anemia (where red blood cells break down too quickly). Other symptoms can include dark urine, pale stools, and fatigue.

GGT is an enzyme found in the liver and is involved in the transport of amino acids and the metabolism of glutathione, an antioxidant. It is highly sensitive to liver and bile duct health.

When Low:

Low GGT levels are typically normal and healthy. They do not usually indicate any health issue and are associated with good liver function.

When High:

Elevated GGT levels may indicate liver disease, bile duct problems, or excessive alcohol intake. High GGT can also be triggered by certain medications. Symptoms may include jaundice, nausea, vomiting, abdominal pain, and general malaise.

Measures the total amount of vitamin B12 in the blood, including both active and inactive forms.

When Low:

Indicates vitamin B12 deficiency, which can cause anemia, fatigue, neurological issues, and memory problems.

When High:

May not always be concerning but can suggest liver disease or supplementation. Needs to be interpreted with active B12 levels.

CRP is a protein produced by the liver in response to inflammation. Measuring CRP levels helps detect acute and chronic inflammatory conditions and assess the risk of cardiovascular diseases.​

When Low:

Low CRP levels are normal and indicate the absence of significant inflammation in the body.​

When High:

Elevated CRP levels suggest the presence of inflammation due to infections, autoimmune diseases, or chronic conditions like heart disease. High-sensitivity CRP tests can help evaluate the risk of cardiovascular events. Persistent elevation warrants further investigation to identify and manage the underlying cause. ​

CK is an enzyme found in the heart, brain, and skeletal muscles. It plays a role in energy production within muscle cells.Measuring CK levels helps assess muscle damage or stress.​

When Low:

Low CK levels are generally not concerning and are considered normal. They may be observed in individuals with low muscle mass or certain neuromuscular conditions.​

When High:

Elevated CK levels indicate muscle damage, which can result from strenuous exercise, muscle injuries, or conditions like myocardial infarction and muscular dystrophy. Symptoms may include muscle pain, weakness, and dark-coloured urine. Persistent elevation requires further evaluation to determine the underlying cause. ​

Testosterone is the primary male sex hormone, crucial for the development of male reproductive tissues, muscle mass, bone density, and red blood cell production. It also plays a role in libido and mood regulation.

When Low:

May result in fatigue, low libido, depression, decreased muscle mass, and infertility. Can be caused by aging, testicular dysfunction, or pituitary issues.

When High:

Can lead to acne, aggressive behaviour, increased muscle mass, or infertility due to suppressed sperm production. May result from testosterone therapy or endocrine disorders.

PSA is a protein produced by the prostate gland, both in normal and cancerous cells. A small amount of PSA normally leaks into the bloodstream.

When Low:

Typically not significant.

When High:

May suggest prostate enlargement, inflammation, or cancer. Clinical context is essential.

Calcium is a vital mineral for building and maintaining strong bones and teeth. It also supports nerve function, muscle contraction, and blood clotting.

When Low:

May cause muscle cramps, tingling, fatigue, or osteoporosis. Often linked to vitamin D deficiency, kidney problems, or hormonal imbalances.

When High:

Could signal overactive parathyroid glands, excessive vitamin D intake, or certain cancers. May cause nausea, confusion, or kidney stones.

Magnesium is a vital mineral involved in over 300 enzymatic reactions, including energy production, muscle and nerve function, and bone health. It is obtained from dietary sources like green leafy vegetables, nuts, seeds, and whole grains.​

When Low:

Magnesium deficiency can lead to symptoms such as muscle cramps, fatigue, weakness, and irregular heart rhythms.Severe deficiency may result in numbness, seizures, or personality changes. Causes include inadequate dietary intake, gastrointestinal losses, certain medications, and chronic illnesses.​

When High:

High magnesium levels are uncommon and usually occur in individuals with kidney dysfunction who cannot excrete excess magnesium. Symptoms of hypermagnesemia include nausea, low blood pressure, muscle weakness, and, in severe cases, cardiac arrest.​

Sodium is an essential electrolyte that helps regulate fluid balance, nerve transmission, and muscle function.

When Low:

Known as hyponatremia, it can cause headache, confusion, nausea, and in severe cases, seizures. Often due to excessive fluid intake, medications, or medical conditions.

When High:

Known as hypernatremia, it can lead to dehydration, high blood pressure, and increased risk of heart disease or stroke.

Ferritin is a protein that stores iron in your cells and releases it when needed. It reflects the body's iron reserves and is often the first indicator of iron deficiency or overload.

When Low: Indicates depleted iron stores, often seen in iron deficiency anemia. Symptoms can include fatigue, weakness, and hair loss.

When High: May suggest iron overload (e.g., hemochromatosis), inflammation, liver disease, or chronic illness. High levels in the absence of infection or inflammation should be further evaluated.

HCR is a ratio of total cholesterol to HDL cholesterol and is a useful indicator of heart disease risk. A lower ratio is generally better.

When Low:

Indicates a favourable balance of good to total cholesterol and a lower risk of cardiovascular disease.

When High:

Suggests a higher risk of heart problems, especially if HDL is low and total cholesterol is high.

HDL, often referred to as "good" cholesterol, helps remove excess cholesterol from the bloodstream, transporting it to the liver for excretion. Higher levels of HDL are associated with a lower risk of heart disease.​

When Low:

Low HDL levels can increase the risk of cardiovascular diseases, including heart attacks and strokes. While low HDL doesn't typically cause symptoms on its own, it is a significant risk factor for atherosclerosis, where arteries become narrowed due to plaque buildup. Regular monitoring and lifestyle changes, such as increased physical activity and dietary adjustments, can help raise HDL levels.

When High:

High HDL levels are generally protective against heart disease. However, extremely high levels may be associated with other health issues, and the benefits of very high HDL levels are still being studied.​

LDL, known as "bad" cholesterol, carries cholesterol to tissues, including the arteries. Elevated LDL levels can lead to plaque buildup in arteries, increasing the risk of heart disease.​

When Low:

Low LDL levels are typically considered beneficial and are associated with a reduced risk of cardiovascular disease. However, extremely low levels may be linked to certain health issues, though this is less common.​

When High:

High LDL levels are a major risk factor for atherosclerosis, heart attacks, and strokes. Lifestyle changes and medications, such as statins, are often recommended to lower LDL levels and reduce cardiovascular risk.​

Non-HDL cholesterol includes all cholesterol types considered atherogenic (promoting plaque formation), such as LDL and very-low-density lipoprotein (VLDL). It's calculated by subtracting HDL from total cholesterol.​

When Low:

Low non-HDL cholesterol levels are generally favorable and indicate a lower risk of cardiovascular disease.​

When High:

High non-HDL cholesterol levels suggest an increased risk of atherosclerosis and heart disease. Management includes lifestyle modifications and possibly medications to reduce cholesterol levels.​

TSH is produced by the pituitary gland and regulates the production of thyroid hormones (T3 and T4) from the thyroid gland. It is a key marker for diagnosing thyroid disorders.

When Low:

Low TSH often indicates hyperthyroidism, where the thyroid is overactive. Symptoms may include irritability, insomnia, palpitations, and weight loss.

When High:

High TSH typically indicates hypothyroidism, where the thyroid is underactive. Symptoms include tiredness, weight gain, depression, slow heart rate, and feeling cold.

FT3 is the active form of thyroid hormone that helps regulate many body processes. It is often measured to assess thyroid function, particularly in suspected cases of hyperthyroidism.

When Low:

Low FT3 may point to hypothyroidism or non-thyroidal illness (a condition where severe illness affects thyroid function without primary thyroid disease). Symptoms include fatigue, slow metabolism, constipation, and sensitivity to cold.

When High:

High FT3 levels are typically seen in hyperthyroidism. Symptoms include anxiety, tremors, palpitations, weight loss, and heat intolerance.

FT4 measures the unbound, active form of thyroxine in the bloodstream. It is essential for metabolism, growth, and development.

When Low:

Low FT4 levels are seen in hypothyroidism, where the thyroid is underactive. Symptoms can include fatigue, weight gain, depression, cold intolerance, and dry skin.

When High:

High FT4 levels indicate hyperthyroidism, where the thyroid is overactive. Symptoms include rapid heartbeat, weight loss, nervousness, sweating, and difficulty sleeping.

Haemoglobin is a protein in red blood cells responsible for transporting oxygen throughout the body. Adequate haemoglobin levels are essential for maintaining energy and overall health.​

When Low

Low haemoglobin levels, or anaemia, can lead to fatigue, weakness, and shortness of breath. Causes include nutritional deficiencies, chronic diseases, or blood loss.​

When High

Elevated haemoglobin levels may result from living at high altitudes, smoking, or conditions like polycythaemia vera.This can increase the risk of blood clots and related complications.​

Haematocrit measures the proportion of red blood cells in the blood. It helps assess the blood's capacity to carry oxygen and can indicate hydration status.​

When Low:

A low haematocrit level suggests anaemia, leading to symptoms like tiredness and dizziness. It may result from blood loss, nutritional deficiencies, or chronic illnesses.​

When High:

High haematocrit levels can occur due to dehydration or conditions that increase red blood cell production. This may thicken the blood, raising the risk of clotting issues.

MCH calculates the average amount of haemoglobin per red blood cell, providing insight into the cell's oxygen-carrying capacity.​

When Low:

Low MCH indicates hypochromic anaemia, commonly due to iron deficiency, leading to symptoms like tiredness and weakness.​

When High:

High MCH may be associated with macrocytic anaemia, often resulting from vitamin B12 or folate deficiencies, causing fatigue and cognitive disturbances.​

MCV measures the average size of red blood cells, aiding in classifying types of anaemia.​

When Low:

Low MCV indicates microcytic anaemia, often caused by iron deficiency or chronic disease, leading to symptoms like fatigue and pallor.​

When High:

High MCV suggests macrocytic anaemia, which may result from vitamin B12 or folate deficiencies, causing fatigue and neurological symptoms.​

MPV measures the average size of platelets, providing information about platelet production in the bone marrow.​

When Low:

Low MPV indicates smaller platelets, which may be associated with conditions like aplastic anaemia or certain inherited disorders, potentially leading to bleeding issues.​

When High:

High MPV suggests larger, more reactive platelets, often seen in conditions like immune thrombocytopenia.

Platelets are cell fragments essential for blood clotting, preventing excessive bleeding.​

When Low:

Low platelet counts (thrombocytopenia) can lead to easy bruising, prolonged bleeding, and are associated with conditions like immune thrombocytopenia or bone marrow disorders.​

When High:

High platelet counts (thrombocytosis) may increase the risk of clotting events and can be reactive (due to inflammation) or primary (due to bone marrow disorders).​

RDW assesses the variation in red blood cell sizes, aiding in diagnosing different types of anaemia.​

When Low:

A low RDW is generally not clinically significant and often indicates uniform red blood cell size.​

When High:

High RDW suggests a mix of red blood cell sizes, which can occur in iron deficiency anaemia or vitamin B12/folate deficiencies, leading to fatigue and weakness.​

Basophils are a type of white blood cell involved in allergic reactions and inflammatory responses. They release histamine and other chemicals during immune responses.

When Low:

Low basophil counts are generally not concerning and may be a normal variation. They can also occur with stress or infections.

When High:

High basophils may be associated with allergies, chronic inflammation, or myeloproliferative disorders like chronic myeloid leukemia.

This represents the proportion of basophils relative to total white blood cells. It helps assess allergic and immune responses.

When Low:

A low percentage is typically not clinically significant. Basophils naturally occur in low numbers.

When High:

Elevated basophil percentage may point to chronic allergic reactions, parasitic infections, or hematological disorders.

Eosinophils help fight parasites and are involved in allergic reactions. They play a key role in inflammation and asthma.

When Low:

A low count is often normal but may also be seen during steroid use or stress responses.

When High:

High eosinophils can suggest allergies, asthma, parasitic infections, or certain cancers.

Indicates eosinophils as a percentage of the total white blood cell count. It helps assess allergic or parasitic activity.

When Low:

May reflect stress, acute infections, or use of corticosteroids.

When High:

Suggests conditions like asthma, hay fever, eczema, or parasitic infections.

Lymphocytes are white blood cells critical to the immune system, particularly in fighting viral infections. They include T cells, B cells, and natural killer cells.

When Low:

Lymphopenia may result from autoimmune diseases, corticosteroid use, or infections like HIV. It weakens the immune response.

When High:

Elevated lymphocytes often indicate viral infections, certain bacterial infections, or chronic lymphocytic leukemia.

This measures lymphocytes as a proportion of the total white blood cells. It's useful in evaluating immune function.

When Low:

May occur in acute stress, bacterial infections, or following chemotherapy.

When High:

Suggests chronic viral infection or lymphocytic leukemia.

Monocytes are white blood cells that digest pathogens and damaged cells. They are part of the body's first line of defense.

When Low:

May be caused by bone marrow suppression or severe infections. It can reduce the body’s ability to respond to infection.

When High:

High monocytes can signal chronic infections, inflammatory conditions, or autoimmune diseases.

Indicates monocytes as a proportion of total white blood cells. It helps detect immune and inflammatory activity.

When Low:

May reflect bone marrow suppression or an acute immune reaction.

When High:

Suggests chronic infection, inflammation, or hematologic diseases.

Neutrophils are the most abundant white blood cells and are essential in fighting bacterial infections. They are the first responders to inflammation.

When Low:

Neutropenia may result from bone marrow problems, chemotherapy, or viral infections. It increases the risk of serious infections.

When High:

Elevated neutrophils typically indicate bacterial infection, physical or emotional stress, or inflammation.

This is the proportion of neutrophils among total white blood cells. It’s useful in evaluating acute infections or inflammation.

When Low:

May occur in viral infections or with bone marrow suppression.

When High:

Often seen in bacterial infections, stress, or chronic inflammation.

Alanine Transferase (ALT) is an enzyme primarily found in the liver. It plays a crucial role in converting proteins into energy for liver cells. ALT levels in the blood are a marker of liver health, as they can rise when liver cells are damaged.

When Low:

Low ALT levels are generally considered normal and are not usually a cause for concern. They are typically not associated with any specific symptoms or health conditions. However, in rare cases, very low levels could indicate a vitamin B6 deficiency, which might cause fatigue, irritability, and nerve problems.

When High:

High ALT levels often indicate liver damage or inflammation. Conditions associated with elevated ALT include hepatitis, fatty liver disease (both alcoholic and non-alcoholic), liver cirrhosis, or liver injury from medication or toxins. Symptoms could include fatigue, abdominal pain, jaundice (yellowing of the skin and eyes), and unexplained weight loss.

AST is another enzyme found in the liver, heart, muscles, and other tissues. It is released into the bloodstream when these tissues are damaged.

When Low:

Low AST levels are generally not concerning and often reflect normal healthy tissue function. They do not usually cause symptoms or indicate disease.

When High:

Elevated AST levels can indicate liver disease (such as hepatitis or cirrhosis), muscle damage (from injury or conditions like muscular dystrophy), or heart conditions such as a heart attack. Symptoms vary depending on the cause but may include fatigue, muscle weakness, abdominal pain, and jaundice.

WBC measures the total number of white blood cells, which are crucial for fighting infections and regulating the immune system. It’s a core component of a complete blood count (CBC).

When Low:

Leukopenia may be due to bone marrow disorders, autoimmune diseases, or severe infections. It increases susceptibility to infections.

When High:

Leukocytosis is usually caused by infection, inflammation, trauma, or certain cancers like leukemia.

The red cell count indicates the number of red blood cells in the blood, which are crucial for oxygen transport. This test helps diagnose various conditions, including anaemia and polycythaemia.​

When Low:

A low red cell count can cause fatigue and weakness, often due to anaemia from factors like iron deficiency or chronic disease.​

When High:

An elevated red cell count may be a response to low oxygen levels or disorders like polycythaemia vera, potentially leading to increased blood viscosity and clotting risks.​

Creatinine is a waste product produced by muscles from the breakdown of a compound called creatine. It is filtered out of the blood by the kidneys, making it a key indicator of kidney function.

When Low:

May occur due to reduced muscle mass, liver disease, or a very low-protein diet. While not typically concerning, it may indicate underlying health issues if extremely low.

When High:

Suggests impaired kidney function or kidney disease, as the kidneys are not effectively filtering waste from the blood. It may also rise temporarily due to dehydration or high protein intake.

eGFR is a calculation based on creatinine levels, age, sex, and race, providing an estimate of how well the kidneys are filtering waste from the blood.​

When Low:

A low eGFR indicates reduced kidney function, which may be due to acute or chronic kidney disease. Symptoms can include fatigue, swelling, and changes in urination.​

When High:

A high eGFR is generally considered normal, especially in younger individuals. However, extremely high values may be seen in pregnancy or in individuals with very low muscle mass.​

Urea is a waste product formed in the liver from the breakdown of proteins and is excreted by the kidneys. Measuring urea levels helps assess kidney function and protein metabolism.​

When Low:

Low urea levels are uncommon and usually not a cause for concern. They can occur in severe liver disease, malnutrition, or during pregnancy. Low urea levels are also seen in infants and small children.​

When High:

High urea levels suggest poor kidney function, which may be due to acute or chronic kidney disease. However, other factors such as decreased blood flow to the kidneys (e.g., in congestive heart failure, shock, or severe burns), gastrointestinal bleeding, urinary tract obstructions, or dehydration can also elevate urea levels. ​

Cholesterol is a fatty substance essential for building cell membranes and producing hormones. It is carried in the blood by lipoproteins, mainly low-density lipoprotein (LDL) and high-density lipoprotein (HDL).​

When Low:

Low cholesterol levels are uncommon but may be associated with malnutrition, liver disease, or certain genetic disorders.Symptoms can include depression, anxiety, and hormonal imbalances.​

When High:

High cholesterol levels, particularly elevated LDL (bad cholesterol), increase the risk of atherosclerosis, heart attack, and stroke. High-density lipoprotein (HDL) is considered good cholesterol and helps remove excess cholesterol from the bloodstream.

Vitamin D is crucial for calcium absorption, bone health, immune function, and muscle strength. It is synthesized in the skin upon exposure to sunlight and is also found in foods like oily fish, fortified cereals, and dairy products. In the UK, limited sunlight exposure, especially during winter months, can lead to widespread vitamin D insufficiency. ​

When Low:

Vitamin D deficiency can result in bone disorders such as rickets in children and osteomalacia in adults, leading to bone pain and muscle weakness. Other symptoms include fatigue, frequent infections, depression, and impaired wound healing.Risk factors for deficiency include limited sun exposure, darker skin tones, obesity, and certain medical conditions affecting absorption.

When High:

Excessive vitamin D levels, often due to over-supplementation, can lead to hypercalcemia, characterized by nausea, vomiting, weakness, and kidney problems. It's important to monitor vitamin D intake and consult healthcare providers before taking high-dose supplements.​

Uric acid is a waste product formed from the breakdown of purines, substances found in certain foods and drinks. It is normally dissolved in the blood and excreted by the kidneys. Monitoring uric acid levels helps assess the risk of gout and kidney stones.​

When Low:

Low uric acid levels are rare and usually not a cause for concern. They may be associated with certain medical conditions like liver disease or exposure to toxic substances, but often do not produce symptoms.​

When High:

Elevated uric acid levels can lead to the formation of urate crystals in joints, causing gout—a type of arthritis characterized by sudden, severe joint pain, redness, and swelling, often in the big toe. High levels may also contribute to kidney stone formation. Factors contributing to high uric acid include a diet rich in purines (red meat, seafood), alcohol consumption, obesity, and certain medications. ​