Blood test guide
A general guide to reading the lines on a blood test report: value, unit, reference range and relationship to nutrition.
- Parameters
- 14 parameters
- Value entry
- None, no interpretation
- Data
- Nothing is sent to the server
Glucose metabolism
Blood lipids
Thyroid
Kidney and uric acid
Vitamins and minerals
What does it measure?
Reflects average blood sugar over the past 2–3 months: the share of haemoglobin in red blood cells bound to glucose. It summarises months, not a single day.
Relationship to nutrition
HbA1c changes over time with the total carbohydrate load and its spread across meals, meal frequency, activity and weight change. After a plan changes, a new value usually needs at least three months. We read HbA1c together with meter readings; they tell different things.
What does it measure?
The amount of glucose in the blood after at least 8 hours of fasting. A snapshot of that morning; it does not show changes through the day.
Relationship to nutrition
Dinner time and content, late-night snacks, sleep and medication can affect the morning value. In the plan we look especially at the evening meal and late eating habits.
What does it measure?
The amount of insulin released by the pancreas while fasting. It only makes sense together with fasting glucose measured at the same time.
Relationship to nutrition
High fasting insulin is often associated with insulin resistance. Meal intervals, refined carbohydrates and sugary drinks, waist circumference and activity are the main lifestyle factors linked to it.
What does it measure?
Not a test but a calculation: fasting glucose (mg/dL) × fasting insulin (µIU/mL) / 405. A simple indicator used to estimate insulin resistance.
Relationship to nutrition
HOMA-IR varies with age, weight, ethnicity and laboratory method, so no decision is made on a single value. Meal pattern, fibre and protein, sleep and activity are related factors. We read it together with waist, HbA1c and blood lipids.
What does it measure?
The cholesterol carried in low-density lipoproteins. The most studied blood lipid in relation to vascular health.
Relationship to nutrition
Saturated fat (butter, tail fat, processed meat, a lot of full-fat cheese) and trans fat tend to raise LDL. Soluble fibre in oats and legumes and unsaturated fats such as olive oil and walnuts are the key dietary changes. Genetics is a strong factor; diet alone may not be enough.
Related areasHigh cholesterol and triglycerides
The full LDL pageWhat does it measure?
The cholesterol in high-density lipoproteins, which help carry excess cholesterol from tissues back to the liver.
Relationship to nutrition
Regular activity, stopping smoking, reducing excess weight and cutting refined carbohydrates are the main factors linked to HDL. Avoid trans fats and prefer unsaturated fats.
Related areasHigh cholesterol and triglycerides
The full HDL pageWhat does it measure?
Triglycerides make up most of the fat in the blood; the liver produces them from unused calories, sugar and alcohol.
Relationship to nutrition
Triglycerides respond quickly to diet. Sugary drinks, white flour and sweets, alcohol and large portions tend to raise them; oily fish, fibre and regular activity are linked to lower values.
What does it measure?
The pituitary hormone that drives the thyroid. TSH rises when thyroid hormones fall and falls when they rise.
Relationship to nutrition
TSH reflects thyroid function and medication dose more than diet. Adequate iodine (iodised salt, dairy, fish), selenium and iron matter. Taking thyroid medication with coffee, calcium or iron can reduce absorption.
Related areasThyroid conditions
The full TSH pageWhat does it measure?
The free (unbound) part of the main hormone released by the thyroid.
Relationship to nutrition
fT4 is read together with TSH. Diet has limited direct effect, but iodine deficiency or excess (supplements, seaweed products) can affect thyroid function.
Related areasThyroid conditions
The full sT4 pageWhat does it measure?
An estimate of how well the kidneys filter blood, calculated from creatinine, age and sex. Higher means better filtering.
Relationship to nutrition
As kidney function falls, protein, potassium, phosphorus and sodium intake matter more, but the limits are set by the doctor based on stage, urine protein and other tests. Creatinine depends on muscle mass, so the estimate can drift in very muscular or very thin people.
Related areasNutrition in kidney disease
The full eGFR pageWhat does it measure?
A waste product formed when substances called purines are broken down; excreted by the kidneys.
Relationship to nutrition
Organ meats, some seafood, a lot of red meat, alcohol (especially beer) and fructose-sweetened drinks tend to raise uric acid. Enough fluid and reducing excess weight are linked to lower values.
Related areasNutrition in kidney disease
The full Ürik asit pageWhat does it measure?
An indicator of the body's iron stores. Low ferritin suggests depleted stores.
Relationship to nutrition
Red meat, legumes and dark leafy greens provide iron; plant iron is absorbed better with vitamin C and worse with tea and coffee. After bariatric surgery iron absorption can fall, so it is monitored regularly.
Related areasBefore and after bariatric surgery
The full Ferritin pageWhat does it measure?
A vitamin needed for the nervous system and blood formation; found naturally only in animal foods.
Relationship to nutrition
Meat, fish, eggs and dairy provide B12. Vegans, long-term users of metformin or stomach acid medication and people after bariatric surgery are at higher risk of deficiency; regular monitoring is advised.
Related areasBefore and after bariatric surgery
The full B12 pageWhat does it measure?
The circulating form that shows the body's vitamin D status. Most is made in the skin with sunlight.
Relationship to nutrition
Food provides limited vitamin D (oily fish, egg yolk, fortified products). Indoor work, covered clothing, excess weight and bariatric surgery raise the risk of low values. Supplements are often needed and planned by a doctor.
This page is general information. Reference ranges vary by laboratory, age, sex and pregnancy; the range on your report is the one that applies. Diagnosis and treatment are carried out by your doctor. No values are entered on this page and no data is sent to the server.
All parameters
| test | unit | reference range | range bar |
|---|---|---|---|
| HbA1cGlycated haemoglobin | % | < 5.7% (adults) | |
| Açlık glukozuFasting plasma glucose | mg/dL | 70–99 mg/dL | |
| İnsülinFasting insulin | µIU/mL | Laboratory-specific; common upper limit ≈ 25 µIU/mL | |
| HOMA-IRInsulin resistance estimate | — | No universal cut-off; studies often use 2.5 |
| test | unit | reference range | range bar |
|---|---|---|---|
| LDLLDL cholesterol | mg/dL | < 100 mg/dL optimal (general) | |
| HDLHDL cholesterol | mg/dL | Men > 40, women > 50 mg/dL | |
| TGTriglycerides | mg/dL | < 150 mg/dL |
| test | unit | reference range | range bar |
|---|---|---|---|
| TSHThyroid-stimulating hormone | mIU/L | About 0.4–4.0 mIU/L (lab-specific) | |
| sT4Free thyroxine | ng/dL | About 0.9–1.7 ng/dL (lab-specific) |
| test | unit | reference range | range bar |
|---|---|---|---|
| eGFREstimated glomerular filtration rate | mL/dk/1,73 m² | ≥ 90 (judged by age) | |
| Ürik asitUric acid | mg/dL | Men ≈ 3.4–7.0, women ≈ 2.4–6.0 mg/dL |
| test | unit | reference range | range bar |
|---|---|---|---|
| FerritinFerritin (iron stores) | ng/mL | Women ≈ 15–150, men ≈ 30–400 ng/mL (lab-specific) | |
| B12Vitamin B12 (cobalamin) | pg/mL | About 200–900 pg/mL (lab-specific) | |
| 25(OH)DVitamin D (25-hydroxyvitamin D) | ng/mL | ≥ 30 ng/mL sufficient (Endocrine Society) |