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Hormones8 min read

Menopause: which hormones can you have tested?

From around the age of forty-five all sorts of things change: your cycle becomes unpredictable, you sleep worse and you sometimes barely recognise your own mood. The question that follows is a logical one: can I have this measured? What hormone testing during the menopause does offer, and where it falls short.

Values: FSH · Oestradiol · LH · Progesterone

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Liver8 min read

Raised liver values: what do ALT and AST mean?

Seeing that your liver values are raised is unsettling. Yet a mild rise is often harmless and temporary, and a single measurement says little without context. What ALT and AST actually measure, which causes are most common and when looking further is genuinely needed.

Values: Liver enzymes (ALT + AST) · Gamma-GT · Alkaline phosphatase · Bilirubin

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Sport8 min read

Blood testing for athletes: which values say something about recovery?

You train consistently, yet your performance stalls or your legs stay heavy. So you start looking. Blood testing can provide part of the answer, provided you measure the right values at the right moment. Which tests matter for athletes, and which results easily put you on the wrong track.

Values: Ferritin · Iron · Haemoglobin · Creatinine + eGFR

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Stress8 min read

Measuring cortisol under long-term stress: what does it say?

Weeks of taking on too much, sleeping badly and a body that no longer cooperates. The thought that your stress hormone is out of order is an obvious one. You can have cortisol measured, but the result answers a different question than most people expect. Here is what you can and cannot take from it.

Values: Cortisol · TSH · Free T4 · Ferritin

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Vitamins7 min read

Folate (vitamin B11): with a wish to conceive and with fatigue

Folate, also known as vitamin B11 or folic acid in its supplement form, comes up in two very different conversations: around a wish to conceive and around unexplained fatigue. In both cases the question is whether testing helps. The answer differs per situation, and that difference is what this article is about.

Values: Folic Acid · Vitamin B12 · Haemoglobin · Ferritin

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Nutrition8 min read

Eating vegetarian or vegan: which blood values should you check?

A plant-based diet is perfectly sustainable for most people, provided you know which nutrients need attention. A deficiency develops quietly and only causes complaints late on. Which blood values matter for vegetarians and vegans, and when measuring is worthwhile.

Values: Vitamin B12 · Ferritin · Vitamin D · Folic Acid

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Vitamins6 min read

Vitamin B12 deficiency: symptoms, causes and when to test

A vitamin B12 deficiency develops slowly and causes complaints you easily attribute to something else: tiredness, thinking less sharply, tingling in the hands or feet. What the causes are and why only a blood test gives certainty.

Values: Vitamin B12 · Folic Acid · Haemoglobin · Ferritin

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Iron6 min read

Ferritin: what your iron stores say about fatigue and hair loss

Tired for no clear reason, more hair loss than you are used to, or restless legs at night. With those complaints, iron is often the first suspect. Ferritin is the marker that moves first, but it is also the marker most often misread.

Values: Ferritin · Iron · Transferrin · Haemoglobin

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Heart & Vessels6 min read

Testing your cholesterol: what do LDL, HDL and triglycerides tell you?

A cholesterol profile consists of four values, and they do not all tell the same story. What total cholesterol, LDL, HDL and triglycerides actually mean, why doctors focus mainly on LDL and when a measurement is useful.

Values: LDL cholesterol · HDL cholesterol · Total cholesterol · Triglycerides

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Blood sugar5 min read

HbA1c: your average blood sugar over three months

A fasting glucose tells you how your blood sugar stood at that one moment. HbA1c looks much further back, at the average of the past two to three months. What that value measures and who benefits from having it done.

Values: HbA1c · Glucose · Insulin · Haemoglobin

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Fatigue7 min read

Always tired: which blood values should you have tested?

Everyone is tired now and then. If the fatigue lasts for weeks even though you sleep enough, it makes sense to think about your blood. Which blood values tell you the most with persistent tiredness, and when a blood test is precisely not the answer.

Values: Ferritin · TSH · Free T4 · Vitamin B12

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Hair & Skin7 min read

Hair loss: which blood values can play a role?

More hair in your brush or on your pillow than you are used to. Hair loss often has an innocent or hereditary explanation, but sometimes a deficiency or a hormonal shift plays a part that can be seen in blood. Which blood values can play a role, and what a blood test does and does not tell you.

Values: Ferritin · Iron · TSH · Free T4

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Symptoms7 min read

Dizzy: when is a blood test worthwhile?

Dizziness has many faces: the room spinning, feeling light-headed when standing up, or being unsteady on your feet. The cause often lies in the balance organ or blood pressure regulation, and sometimes in the blood. When a blood test is worthwhile, which values tell you the most, and with which signals you should not wait.

Values: Haemoglobin · Glucose · Sodium · Potassium

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Blood sugar7 min read

Excessive thirst and frequent urination: check your blood sugar

A bottle of water always within reach, and waking up at night to go to the toilet. It is a combination that is easily dismissed, while it can be one of the first signals of a raised blood sugar. What glucose and HbA1c tell you, and when you should not wait for a result.

Values: Glucose · HbA1c

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Thyroid7 min read

An abnormal TSH: what does it mean?

TSH is almost always the first value measured when the thyroid comes to mind. If your result is flagged as abnormal, the first question is not what you have, but what else is needed to know that. What TSH actually measures, and why the result works the opposite way to what you might expect.

Values: TSH · Free T4 · Free T3 · Anti-TPO

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Iron7 min read

Iron or ferritin: what is the difference?

Having your iron tested sounds simple, but there are three ways of looking at it and they do not give the same answer. What serum iron, ferritin and transferrin each measure, why inflammation can distort the picture, and when each test genuinely helps you further.

Values: Ferritin · Iron · Transferrin · CRP

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Heart & Vessels7 min read

ApoB and Lp(a): looking beyond your cholesterol

A cholesterol profile gives a good first impression, but it does not tell you everything. ApoB shows how many particles are actually travelling through your blood vessels. Lp(a) reveals a largely inherited risk that lifestyle barely changes. What both values add and who they are useful for.

Values: LDL cholesterol · Total cholesterol · HDL cholesterol · Triglycerides

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Kidneys7 min read

Testing kidney function: what do eGFR and creatinine tell you?

Your kidneys do their work without you noticing, and that is exactly the problem: if they start working less well, you often feel it only late. Creatinine and eGFR are the values used as standard to assess kidney function. What they measure, where they fall short and when testing is useful.

Values: Creatinine + eGFR · Cystatin C · Urea · Uric acid

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Inflammation7 min read

CRP: what does this inflammation marker tell you?

CRP is one of the most frequently requested blood values and at the same time one of the most misunderstood. It shows that inflammation is present in your body, but not where and not why. What CRP does and does not tell you, what hsCRP adds and when measuring is worthwhile.

Values: CRP · ESR (sedimentation rate) · Haemoglobin · Ferritin

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Minerals6 min read

Magnesium deficiency: symptoms and when to test

Muscle cramps that wake you at night, an eyelid that keeps twitching, tiredness that will not pass. A magnesium deficiency is rarely the first suspect, yet this mineral is involved in hundreds of processes in the body. Which complaints fit, what the causes are and why a blood test only tells part of the story.

Values: Magnesium · Calcium · Potassium · Ferritin

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Costs7 min read

How much does a blood test cost in 2026?

What a blood test costs depends mainly on two things: which route you take and how many and which markers are measured. In this article we set both routes out honestly, with real prices, so you know where you stand in advance.

Values: Potassium · Sodium · Liver enzymes (ALT + AST) · Vitamin B12

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Hormones7 min read

Hormone testing for women: what can you measure?

An irregular cycle, mood swings, hot flushes or persistent fatigue: many complaints are quickly blamed on hormones. Rightly or not? A blood test can give part of the answer, provided you measure the right hormones at the right moment. This is what you can measure, and what you can and cannot expect from it.

Values: Oestradiol · Progesterone · FSH · LH

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Kidneys5 min read

Cystatin C: a more accurate look at your kidney function

Creatinine has been the standard for estimating kidney function for years. But in people with high or low muscle mass, it sometimes gives a distorted picture. Cystatin C largely solves that problem. What it measures and when it is useful.

Values: Cystatin C · Creatinine + eGFR · Urea · Uric acid

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Men's Health7 min read

PSA test: what it measures and when it makes sense

The PSA test is the only blood test that can indicate prostate cancer. But an elevated value is not a diagnosis, and testing has both advantages and disadvantages. What you need to know.

Values: PSA

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Vitamins & Minerals5 min read

Vitamin D deficiency: causes, symptoms and when to test

Vitamin D deficiency is common in the Netherlands, particularly in the winter months. But how do you know whether you have a deficiency yourself? And when does testing actually make sense?

Values: Vitamin D · Calcium · Magnesium · Vitamin B12

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Hormones6 min read

Testosterone testing: what it measures and when it makes sense

Fatigue, reduced libido, or muscle loss: testosterone is quickly identified as the cause. But a blood test tells you far more than any self-diagnosis ever can.

Values: Testosterone · Free testosterone · SHBG · LH

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Thyroid5 min read

Thyroid and fatigue: what does your blood tell you?

Persistent fatigue can have dozens of causes. The thyroid is one of them, and relatively easy to measure. What to expect from a thyroid test.

Values: TSH · Free T4 · Anti-TPO · Ferritin

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Weight Loss & Metabolism7 min read

GLP-1, Ozempic, and medical weight loss: what can you have tested?

GLP-1 agonists such as semaglutide are very much in the spotlight. But those who use them, or are considering doing so, benefit from insight into a number of blood values. What you need to know.

Values: HbA1c · Glucose · Insulin · Liver enzymes (ALT + AST)

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