Blood TESTS

What does it all mean?

This is a list of some of the blood tests you might have and a few different explanations of why you might be having them. It’s not exhaustive but gives a big of information.

Liver function tests

Albumin - Albumin is a protein produced by the liver and plays a critical role in maintaining a health fluid balance in the body as well as transporting hormones, medications, and nutrients.

ALP - alkaline phosphatase is an enzyme produced in the liver and bones. Elevated ALP can indicate liver, bone or gall bladder issues.

ALT - Alanine aminotransferase (ALT) is a produced by liver cells. Elevated levels of ALT in the bloodstream can indicate liver damage or injury, such as that caused by hepatitis, alcohol consumption, or certain medications. Abnormal ALT levels may indicate a variety of medical conditions, such as hepatitis or non-alcoholic fatty liver disease (NAFLD).

GGT - Gamma-glutamyl transferase (GGT) is produced in the liver, pancreas, kidneys, and spleen. Raised GGT can indicate liver damage can can be caused by long term high alcohol consumption, viruses, or medications. GGT levels can also rise if the bile ducts are obstructed.

Globulin - Globulins are proteins in the blood that support the immune system, blood clotting process, and the transport of hormones and lipids. They can be raised by infection, inflammation, dehydration, liver cirrhosis or multiple myeloma. They can be low due to kidney or liver problems or malnutrition.

Bilirubin - Bilirubin is a yellow pigment formed as a byproduct of the breakdown of haemoglobin (the protein in red blood cells that carries oxygen). Bilirubin is produced in the liver and is excreted in the bile and is then eliminated from the body in the stool. Raised bilirubin can be caused by a myriad of conditions including gall stones, alcoholic liver disease, autoimmune conditions and medications. When raised it can cause jaundice (yellow discolouration of the skin).

Lipids

Total cholesterol is the sum of all types of cholesterol in the blood, including low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol.

LDL Cholesterol - LDL cholesterol, sometimes referred to as "bad" cholesterol, is a type of cholesterol that can contribute to the buildup of plaque in the arteries, increasing the risk of heart disease and stroke.

HDL Cholesterl - HDL cholesterol, often referred to as "good" cholesterol, is a type of cholesterol that helps to remove excess cholesterol from the bloodstream, reducing the risk of heart disease and stroke.

Triglycerides - Triglycerides are a type of fat that are used for energy storage in the body. High levels of triglycerides can increase the risk of heart disease and other health conditions.

https://qrisk.org/2017/ can help assess your cardiovascular risk.

Thyroid function test

Thyroid stimulating hormone (TSH) is a hormone produced by the pituitary gland that regulates thyroid gland function and secretion of thyroxine (T4) and triiodothyronine (T3) by the thyroid gland. TSH is measured to assess thyroid function and diagnose thyroid disorders such as hypothyroidism (under achieve) and hyperthyroidism (over active).

Full Blood Count (FBC)

Red blood cells (RBCs) are responsible for carrying oxygen throughout the body. The FBC measures the number and size of the RBCs. Low RBC counts may indicate anaemia, while high RBC counts may indicate  polycythaemia, a condition in which there are too many red blood cells.

Haemoglobin (Hb) - Haemoglobin is a protein in RBCs that used to carry oxygen. The FBC measures the level of haemoglobin in the blood. Low haemoglobin levels may indicate anaemia, while high haemoglobin levels may indicate dehydration or a rare blood disorder.

Haematocrit (Hct) - A measure of the proportion of RBCs in the blood. The FBC measures the percentage of the blood that is made up of RBCs. Low haematocrit levels may indicate anemia, while high haematocrit  levels may indicate polycythaemia or sometimes dehydration at the point of the blood test.
White blood cells (WBCs) are responsible for helping fight infection and disease. High WBC counts can indicate recent infection or inflammation, while low WBC counts may indicate a weakened immune system.

Platelets (PLTs) - Responsible for blood clotting. Low platelet counts may indicate a bleeding disorder, while high platelet counts may indicate a blood clotting disorder.

Eosinophils - Responsible for fighting off parasitic infections and are involved in the body's response to certain allergic reactions. When eosinophil levels are elevated, it may indicate that the body is mounting an immune response to a parasitic infection or an allergic reaction. Eosinophilia be a sign of certain autoimmune or inflammatory disorders.

Lymphocytes - A type of white blood cell that play a critical role in the body's immune system. They recognise and respond to viruses, bacteria, and other pathogens (disease causing organisms). Lymphocytes are measured as part of a full blood count to assess the body's immune system function.

Kidney function tests

Creatinine - A waste product produced by the muscles and excreted by the kidneys. Its measured to assess kidney function. When the kidneys are functioning appropriately, they filter creatinine from the blood and excrete it in the urine. If kidney function is impaired, creatinine levels may increase.

Sodium - An electrolyte, crucial in the body's fluid balance, nerve and muscle function. Its measured to assesss electrolyte balance and kidney function. Sodium levels are tightly regulated, and abnormal levels can indicate underlying health issues.

Urea - A waste product produced by the liver and excreted by the kidneys. It is measured to assess kidney function. Elevated levels can indicate impaired kidney function.

eGFR - Stands for "estimated glomerular filtration rate," and can be used as an assessment of kidney function. The eGFR is calculated based on the level of creatinine in the blood, age, gender, and other factors including weight and race.

HbA1c - Stands for "hemoglobin A1c," which measures the average level of blood sugar (glucose) over the past two to three months. It’s also used to assess and diagnose diabetes. HbA1c is formed when glucose attaches to haemoglobinThe level of HbA1c is a reflection of the average blood glucose levels over the past two to three months, as red blood cells have a lifespan of approximately 120 days.

PSA - Prostate-specific antigen (PSA) is a protein produced by the prostate gland, and is used to assess the health of the prostate gland. It can be used as a screening tool for prostate cancer however, elevated levels can also be caused by benign prostatic hyperplasia (BPH), inflammation of the prostate gland (prostatitis), genitourinary infection or recent ejaculation.

Vitamin D - An essential a fat-soluble hormone produced by when the skin is exposed to UV sunlight. It can also found in foods and supplements.Vitamin D is important in bone health and helping the body absorb calcium. It also supports immune function. Low levels of vitamin D have also been associated with low testosterone levels in men.

Zinc - A mineral involved in many physiological processes, including immune function, wound healing, and the metabolism of protein and carbohydrates.

Folate - A B vitamin and acts as a coenzyme responsible for the metabolism of amino acids as well as purines and pyrimidines, responsible for DNA synthesis and cell growth.

Ferritin
- A protein that stores iron in the body and is found in almost all living organisms. It is found primarily in the liver.Ferritin is used as a marker of iron stores in the body, because  it reflects the amount of iron that is stored in the liver and other tissues.

SHBG - Sex hormone-binding globulin (SHBG) is a protein thats made in the liver. It’s involved in regulating the levels of available sex hormones in the blood, particularly testosterone and oestrogen. SHBG binds to these hormones and transports them throughout the body, controlling their bioavailability and subsequent biological activity.  The levels of SHBG in the bloodstream are influenced by various factors, such as age, sex, body fat and certain medical conditions, including obesity and liver disease.

Total Testosterone - When SHBG binds to testosterone, it forms a complex that cannot freely diffuse into cells, reducing the amount of biologically active testosterone available. Approximately 68% of testosterone is bound to SHBG with high affinity and about 20–30% is weakly bound to albumin. Only the remaining 1-2% is free or unbound.

Free Testosterone - Free testosterone refers to the bioavailable or active portion of testosterone that is not bound to sex hormone-binding globulin (SHBG) or albumin in the bloodstream. It can freely diffuse into cells and bind to androgen receptors.

Leutenising hormone (LH) - Luetenising hormone is released from the pituitary in the brain to stimulate the testes to produce testosterone.

Follicle stimulating hormone (FSH) - Follicle stimulating hormone is a hormone produced by the pituitary gland that plays an important role in the development and maturation of sperm in men. In men, FSH stimulates the Sertoli cells in the testes to support the growth and development of sperm.

Oestradiol - In men, oestradiol plays an important role in the regulation of bone density, mood, and sexual function. Men produce oestrogen in the Leydig cells and germ cells in the testes. It’s also created from the breakdown of testosterone by the enzyme, aromatase.

Cortisol - Cortisol is a hormone produced by the adrenal glands in response to stress. It plays a vital role in the body's stress response and helps regulate a variety of physiological functions, including blood sugar levels, blood pressure, and immune function.