Optimal Health Blood Test

Cholesterol is an essential fat (lipid) in the body. Although it has a bad reputation it has some important functions, including building cell membranes and producing a number of essential hormones including testosterone and oestradiol. Cholesterol is manufactured in the liver and also comes from the food we eat. Although there are a number of different types of cholesterol, the two main components of total cholesterol are HDL (high density lipoprotein) which is protective against heart disease and LDL (low density lipoprotein) which, in high levels, can contribute to cardiovascular disease. Your total cholesterol result on its own is of limited value in understanding your risk of heart disease; high levels of HDL cholesterol can cause a raised total cholesterol result but may actually be protective against heart disease. Equally, you can have a normal total cholesterol level but have low levels of protective HDL cholesterol. The most important factors are how much HDL and LDL cholesterol you have, and what proportion of your total cholesterol is made up of protective HDL cholesterol. We give a detailed breakdown of the components of your total cholesterol in the rest of this cholesterol profile.

LDL cholesterol (low-density lipoprotein) is a molecule made of lipids and proteins which transports cholesterol, triglycerides and other fats to various tissues throughout the body. Too much LDL cholesterol, commonly called ‘bad cholesterol’, can cause fatty deposits to accumulate inside artery walls, potentially leading to atherosclerosis and heart disease.

Your total cholesterol is broken down into 2 main components; HDL (good) cholesterol and LDL (bad). There are more types of harmful cholesterol in your blood than just LDL – these include VLDL (very low-density lipoproteins) and other lipoproteins which are thought to be even more harmful than LDL cholesterol. Non-HDL cholesterol is calculated by subtracting your HDL cholesterol value from your total cholesterol. It therefore includes all the non-protective and potentially harmful cholesterol in your blood, not just LDL. As such, it is considered to be a better marker for cardiovascular risk than total cholesterol and LDL cholesterol. The recommended level of non-HDL cholesterol is below 4 mmol/L.

HDL cholesterol (high-density lipoprotein) is a molecule in the body which removes cholesterol from the bloodstream and transports it to the liver where it is broken down and removed from the body in bile. HDL cholesterol is commonly known as ‘good cholesterol’.

The cholesterol/HDL ratio is calculated by dividing your total cholesterol value by your HDL cholesterol level. It is used as a measure of cardiovascular risk because it gives a good insight into the proportion of your total cholesterol which is good (i.e. high-density lipoprotein HDL). Heart disease risk tools (such as QRisk) use the cholesterol/HDL ratio to calculate your risk of having a heart attack.

Triglycerides are a type of fat (lipid) that circulate in the blood. After you eat, your body converts excess calories (whether from fat or carbohydrates) into triglycerides which are then transported to cells to be stored as fat. Your body then releases triglycerides when required for energy.

Apolipoprotein A1, or ApoA1, is the main protein found in high-density lipoprotein (HDL) cholesterol. The higher your Apo1 result, the more HDL cholesterol particles you have. HDL cholesterol helps clear cholesterol from the blood by removing cholesterol from organs and tissues to be broken down by the liver.

A low ApoA1 level, especially with a raised ApoB result, is associated with an increased risk of cardiovascular disease. ApoA1, alongside other risk factors, can help to build a picture of your overall cardiovascular risk and likelihood of heart attack and stroke in later years.

Apolipoprotein B, or ApoB, is the main protein found in lipoproteins such as low-density lipoprotein (LDL) cholesterol and ultra-low-density lipoproteins (chylomicrons). Each of these lipoproteins contains one ApoB particle. So, your ApoB levels can tell you the number of these lipoproteins in the blood, which is why ApoB is considered a better predictor of heart disease risk than LDL cholesterol measurements.

ApoB plays a crucial role in transporting lipids (fats) around the body, but too much ApoB is linked to conditions like atherosclerosis, heart attacks, and strokes, which can affect your lifespan and your quality of life in later years.

Your ApoB:ApoA1 ratio is calculated by dividing your ApoB level by your ApoA1 level. It’s considered a better predictor of cardiovascular risk than your individual apolipoprotein results alone, or other cholesterol ratios such as an LDL:HDL ratio.

A higher ratio is linked to an increased risk of heart attacks, vascular disease, and stroke, all of which can impact not just how long you live, but how many years you spend in good health.

Lipoprotein(a), or Lp(a), is a type of lipoprotein made by the liver. Lp(a) is very similar to LDL cholesterol but is more “sticky” as it also contains a protein called Apo(a). Lp(a) is thought to play an important role in the blood’s clotting system, but raised levels are linked to a higher risk of cardiovascular disease, including heart attacks and strokes. Knowing your level can help stratify your risk. The amount of Lp(a) in your blood is determined by your genes and not affected by your age or sex.

Your triglyceride to HDL cholesterol (TG:HDL) ratio, an important heart health marker, is calculated by dividing your triglyceride level by your HDL cholesterol level. An imbalance in these essential fats is associated with an increased risk of cardiovascular disease, insulin resistance, and higher blood sugar levels, all of which can significantly impact not just longevity, but the number of years you spend in good health. The TG:HDL ratio therefore helps to build an even more comprehensive picture of your risk alongside other cholesterol markers.

Platelets or clotting cells are the smallest type of blood cell. They are formed in the bone marrow and are important in blood clotting. When bleeding occurs, the platelets swell, clump together and form a sticky plug (a clot) which helps stop the bleeding.

MPV, or Mean Platelet Volume, is a measurement of the average size of your platelets. Platelets are fragmented cells within the blood that aid the process of clot formation. MPV provides an indication of platelet production in your bone marrow.

Haemoglobin A1c (HbA1c), also known as glycated haemoglobin, is a longer-term measure of glucose levels in your blood than a simple blood glucose test. Glucose attaches itself to the haemoglobin in your red blood cells, and as your cells live for around 12-16 weeks, it gives us a good indication of the average level of sugar in your blood over a 3-month period.

A raised HbA1c result points to diabetes or an increased risk of developing diabetes, which can have a significant impact on your lifespan and quality of life. Complications of uncontrolled diabetes include heart disease, kidney disease, eye problems, and vascular conditions. It can also contribute to mental health problems. And men with diabetes are three times more likely to have erectile dysfunction. Keeping your HbA1c within a normal range can help you reduce the risk of these conditions.

Uric acid is a waste product produced from the breakdown of chemical compounds called purines. Purine occurs naturally in the body, but it is also found in the food we eat – and in some foods more than others. In healthy individuals, uric acid is excreted by the kidneys in urine, however, if levels are too high to excrete, or if you have a problem metabolising purine, then uric acid can begin to accumulate and can be deposited as crystals in the bodily tissues. When this occurs in joints it causes the painful condition known as gout. High levels of uric acid are also linked to metabolic syndrome, a cluster of health problems that increase the risk of heart disease and diabetes.

Follicle Stimulating Hormone (FSH) is produced in the pituitary gland and is important for women in the production of eggs by the ovaries and for men in the production of sperm. In the first half of the menstrual cycle in women, FSH stimulates the enlargement of follicles within the ovaries. Each of these follicles will help to increase oestradiol levels. One follicle will become dominant and will be released by the ovary (ovulation), after which follicle stimulating hormone levels drop during the second half of the menstrual cycle. In men, FSH acts on the seminiferous tubules of the testicles where they stimulate immature sperm cells to develop into mature sperm.

Luteinising Hormone (LH) is produced by the pituitary gland and is important for male and female fertility. In women it governs the menstrual cycle, peaking before ovulation. In men it stimulates the production of testosterone.

Oestradiol is the strongest of the three oestrogens. It’s labelled a female hormone but it’s made in both the ovaries and testes. It’s responsible for the growth of breast tissue, the female reproductive system, and male sexual function.

In pre-menopausal women, oestradiol levels vary throughout the monthly cycle, peaking just before ovulation. Levels are lowest after menopause when the ovaries stop producing eggs. Low oestradiol levels in women can cause many symptoms associated with the menopause, including hot flushes, night sweats, and changes in mood. It can also increase the risk of osteoporosis (a condition where the bones become less dense).

In men, oestradiol levels tend to increase slightly with age as testosterone levels decline. Too much oestradiol in men can contribute to fertility problems, gynecomastia (enlarged breast tissue), and erectile dysfunction.

Testosterone is a hormone that causes male characteristics. For men, it helps to regulate sex drive and has a role in controlling bone mass, fat distribution, muscle mass, strength and the production of red blood cells and sperm. Testosterone is produced in the testicles of men and, in much smaller amounts, in the ovaries of women. Testosterone levels in men naturally decline after the age of 30, although lower than normal levels can occur at any age and can cause low libido, erectile dysfunction, difficulty in gaining and maintaining muscle mass and lack of energy. Although women have much lower amounts of testosterone than men, it is important for much the same reasons, playing a role in libido, the distribution of muscle and fat and the formation of red blood cells. All laboratories will slightly differ in the reference ranges they apply because they are based on the population they are testing. The normal range is set so that 95% of men will fall into it. For greater consistency, we use the guidance from the British Society for Sexual Medicine (BSSM) which advises that low testosterone can be diagnosed when testosterone is consistently below the reference range, and that levels below 12 nmol/L could also be considered low, especially in men who also report symptoms of low testosterone or who have low levels of free testosterone.

Most testosterone circulating in the blood is bound to proteins, in particular SHBG and albumin; only 2-3 % of testosterone is free and available to cells. This test uses an algorithm to calculate the level of free or unbound testosterone in relation to total testosterone, SHBG and albumin.

The free androgen index (FAI) is a calculation used to determine the amount of testosterone which is free (unbound) in the bloodstream. Most testosterone is bound to proteins sex hormone binding globulin and albumin and is not available to interact with the body’s cells. The FAI is a calculation based on the ratio of testosterone and SHBG and is a measure of the amount of testosterone that is available to act on the body’s tissues. The free androgen index is used in women to assess the likelihood of polycystic ovarian syndrome. In men, free testosterone gives a better indication of testosterone status.

C-Reactive Protein (CRP) is an inflammation marker used to assess whether there is inflammation in the body – it does not identify where the inflammation is located. High Sensitivity CRP (CRP-hs) is a test used to detect low-level inflammation thought to damage blood vessels which can lead to a heart attack or stroke. When you suffer a serious injury or infection you experience significant inflammation around the site of injury – such as the swelling around a twisted ankle. Any injury like this will cause your CRP-hs to rise.

Iron is a mineral that is essential for life. It is a component of haemoglobin, a protein in our red blood cells that is responsible for transporting oxygen around our body. If we don’t have enough iron, our haemoglobin levels fall and we can’t get sufficient oxygen to our cells. This can cause symptoms which include fatigue, dizziness, and shortness of breath. Serum iron is a very transient reading and can be influenced by the amount of iron-rich food in your diet in the days before your blood test. For this reason, iron is rarely looked at on its own, and is interpreted alongside other markers in an iron status test.

Total iron-binding capacity (TIBC) is a measure of the ability of your body to efficiently carry iron through the blood.

Transferrin is made in the liver and is the major protein in the blood which binds to iron and transports it round the body. This test measures how much this protein is ‘saturated’ by iron.

Ferritin is a protein which stores iron in your cells and tissues. Usually, the body incorporates iron into haemoglobin to be transported around the body, but when it has a surplus, it stores the remaining iron in ferritin for later use. Measuring ferritin levels gives us a good indication of the amount of iron stored in your body.

Unsaturated iron binding capacity (UIBC) represents the portion of iron binding sites on transferrin that are not occupied by iron. UIBC is often measured along with iron and total iron-binding capacity (TIBC) as a diagnostic tool to determine various iron disorders.

Urea is a waste product produced by the body when it breaks down proteins in the liver. Once the urea is made, it is transported to the kidneys, which filter it out of the blood and remove it from the body in the form of urine. Measuring the levels of urea in the blood can therefore reflect how well both the liver and the kidneys, are functioning. It is important to note that even if one kidney is severely damaged but the other is functioning perfectly, results may still return as normal.

Creatinine is a chemical waste molecule that is generated from normal muscle metabolism. Measurement of this is an indicator of the levels of other waste products in the body. Creatinine is also an accurate marker of kidney function, and may help in diagnosing kidney disease.

The estimated glomerular filtration rate (eGFR) assesses how well the kidneys are working by estimating the amount of blood filtered through the kidneys. The glomeruli are tiny filters in the kidneys responsible for removing waste products. If these filters do not do their job properly, kidney function can be impaired. The eGFR calculation is an estimate of actual glomerular filtration rate, calculated using your age, gender, ethnicity, and serum creatinine levels.

Bilirubin is a product of the breakdown of haemoglobin from red blood cells. It is removed from the body via the liver, stored and concentrated in the gallbladder and secreted into the bowel. It is removed from your body through urine and faeces. Bilirubin causes the yellowish colour you sometimes see in bruises, due to red blood cells breaking down underneath the skin.

Alkaline phosphatase (ALP) is an enzyme found mainly in the liver and bones. Measuring it can indicate ongoing liver, gallbladder or bone disease.

Alanine transferase (ALT) is an enzyme which is mostly found in the liver, but is also found in smaller amounts in the heart, muscles and the kidneys. If the liver is damaged, ALT is leaked into to bloodstream. As ALT is predominantly found in the liver, it is usually an accurate marker for liver inflammation and can indicate liver damage caused by alcohol, fatty liver, drugs or viruses (hepatitis).

Gamma GT, also known as gamma-glutamyl transferase (GGT), is a liver enzyme which is raised in liver and bile duct diseases. It is used in conjunction with ALP to distinguish between bone or liver disease. Gamma GT is also used to diagnose alcohol abuse as it is raised in 75% of long term drinkers.

Total Protein represents the sum of the proteins albumin and globulin in your blood. Albumin and globulin have a range of functions including keeping blood within vessels, transporting nutrients and fighting infection. Abnormal levels can indicate malnutrition as well as a liver or kidney disorder.

Albumin is a protein which is made mainly in the liver. It helps to exert the osmotic pressure which holds water within the blood. It also helps carry nutrients and medications and other substances through the blood and is important for tissue growth and healing. Albumin also carries hormones around the body, therefore measuring the amount of albumin in the blood can help us calculate how much hormone is available to your tissues.

Globulin is an umbrella term for a set of different proteins that the immune system and the liver produce. Certain globulins bind with haemoglobin while others transport metals, such as iron, in the blood. Additionally, there is a certain type of globulin known as an immunoglobulin, (another name for an antibody) which helps to fight infection in the body.

SHBG (sex hormone binding globulin) is a protein which transports the sex hormones (testosterone, oestrogen and dihydrotestosterone (DHT)) in the blood.Hormones which are bound to SHBG are inactive which means that they are unavailable to your cells. Measuring the level of SHBG in your blood gives important information about your levels of free or unbound hormones which are biologically active and available for use.

Haemoglobin is a protein in red blood cells which carries oxygen around the body and gives the blood its red colour. This test measures the amount of haemoglobin in the blood and is a good measure of the blood’s ability to carry oxygen around the body.

HCT (haematocrit) measures the amount of space (volume) within the blood that is taken up by red blood cells.

Red Blood Cell (RBC) Count analyses the number of red blood cells in the blood. Red blood cells carry oxygen from the lungs to the rest of the body, where it can be used to fuel energy processes such as movement and respiration. They also carry carbon dioxide produced from cells back to the lungs so that it can be exhaled.

MCV (mean corpuscular volume) reflects the average size of your red blood cells. This is important to measure, as it can indicate how much oxygen your cells are likely to be transporting around the body.

MCH (mean corpuscular haemoglobin) measures the average amount of haemoglobin contained in one of your red blood cells.

MCHC (mean corpuscular haemoglobin concentration) is the average concentration of haemoglobin in your red blood cells. Haemoglobin is a molecule which allows red blood cells to transport oxygen around the body.

Red blood cell distribution width (RDW) indicates whether your red blood cells are all the same size, or different sizes or shapes. Normally cells are fairly uniform both in size and in shape, but some blood disorders may cause your red blood cells to form in abnormal sizes. This test measures the difference between the largest and the smallest red blood cell.

Thyroid stimulating hormone (TSH) is produced in the pituitary gland in order to regulate the production of thyroid hormones thyroxine (T4) and triiodothyronine (T3) by the thyroid gland. If thyroid hormones in the blood are low, then more TSH is produced to stimulate the thyroid gland to produce more of them. If thyroid hormone levels are high, then the pituitary produces less TSH to slow the production of thyroid hormones. If TSH is too high or too low, it normally signifies that there is a problem with the thyroid gland which is causing it to under or over produce thyroid hormones. Sometimes a disorder of the pituitary gland can also cause abnormal TSH levels.

Triiodothyronine (T3) is the more active of the two thyroid hormones produced by the thyroid gland. Most T3 is bound to protein in the blood. Free T3 measures the level of T3 that is free, or unbound to protein, and is available to regulate metabolism.

Thyroxine (T4) is one of two hormones produced by the thyroid gland. It works to speed up the rate of your metabolism. Most T4 is bound to carrier proteins in the blood – it is only the free, or unbound, T4 that is active in the body, which is measured in this test. Free T4 is the less active of the two main thyroid hormones. To have an impact on your cells it needs to convert to the more active T3 when your body needs it.

Folate is a B vitamin which acts as a coenzyme in the metabolism of amino acids. It is also vital for the synthesis of purines and pyrimidines which are essential for DNA synthesis and red cell formation. Folate is also especially important during the first trimester of pregnancy so if you are thinking of becoming pregnant it is important to make sure your folate levels are normal.

Vitamin B12 is important for production of red blood cells which carry oxygen around the body. B12 is also involved in metabolism and the nervous system and prolonged lack of vitamin B12 may cause nerve damage. Although Vitamin B12 is almost entirely found in animal-based foods, many vegetarian and vegan products, especially plant milks are now fortified with Vitamin B12.

Despite its name, vitamin D is actually a hormone that’s produced by your skin when it’s exposed to sunshine. Before your body can use vitamin D produced by sun exposure (known as vitamin D3), it must be converted into another form called 25 hydroxycholecalciferol (25 OH). Vitamin D (25 OH) is the major circulating form of vitamin D, and so your vitamin D (25 OH) level is considered the most accurate indicator of vitamin D supply to your body.

Vitamin D is essential for healthy bones and teeth, as it helps your body absorb calcium. It also plays a role in muscle health, immune function, and mental health.

Low vitamin D symptoms include muscle weakness, mood swings, and fatigue. Many people in the UK have low vitamin D levels, and people with dark skin and people who don’t spend much time outdoors are particularly at risk.

Small amounts of vitamin D can be obtained from food, especially oily fish, eggs, and vitamin-D fortified foods. But if you have a vitamin D deficiency, you’re unlikely to be able to improve your levels by food alone.