Blood test guides · UK

Your results, in plain English.

Your blood test came back with numbers. These guides explain what they actually mean: written for UK patients, grounded in NHS and NICE guidance, without the jargon.

01

Start here: reading your results

Getting started10 min read Blood test results explained: a plain English guide for UK patients What do the columns mean? What are reference ranges? Why does normal sometimes feel wrong? A complete guide to reading your results. → Getting started8 min read How to read blood test results: units, ranges and flags explained H and L flags, mmol/L versus g/L, reference ranges that vary by lab. A practical guide to making sense of what is on the page. → NHS results8 min read NHS blood test results explained: what your GP sees and what you don't NHS results often arrive with little explanation. What your GP is looking at, what the flags mean, and which questions are worth asking. →
02

Blood sugar & metabolic health

HbA1c7 min read HbA1c normal range UK: what your result actually means The NHS uses 48 mmol/mol as its diabetes threshold. Here is what your number means if you sit below it, and what counts as prediabetes. → Cholesterol8 min read Cholesterol levels explained: total, LDL, HDL and triglycerides Your cholesterol result is four numbers, not one. What each one means, and why the ratio matters more than the total. →
03

Iron & energy

Ferritin7 min read Ferritin levels UK: what's normal, what's low, and what to do Ferritin is your iron store, not the same as iron itself. The NHS range is wide, and many people feel symptoms well before they hit the floor. → Ferritin6 min read Low ferritin symptoms: why you feel tired when your result is "normal" Fatigue, hair loss, brain fog: low ferritin can cause all of these even when your result sits within range. Here is why. → Ferritin · Iron5 min read Low ferritin with normal haemoglobin: what it means and what causes it If you've received blood test results showing low ferritin but normal haemoglobin, you might be wondering what this combination means. →
04

Vitamins & deficiencies

Vitamin D7 min read Vitamin D deficiency symptoms UK: what your blood test shows Over 1 in 5 UK adults are vitamin D deficient. What the numbers mean, which symptoms to expect, and when supplementing makes sense. → Vitamin D6 min read Vitamin D blood test results: reading your 25-OH-D level Your vitamin D result is reported as 25-hydroxyvitamin D. What the number means, what the NHS considers deficient, and what optimal looks like. →
05

Hormones & conditions

PCOS9 min read PCOS blood test results: what to look for and what the ranges mean PCOS diagnosis involves several markers: LH, FSH, testosterone, AMH and insulin. How to read each one, and what the pattern means together. → CRP · Inflammation7 min read Your CRP Blood Test is High — What Does It Mean? If you've recently had a blood test and noticed that your CRP (C-reactive protein) levels are high, you might be feeling concerned. It's natural to worry about what this result could mean for your health. → Blood test guide7 min read Liver function test results explained: what it measures and what your results mean When you receive your liver function test results, it's natural to feel a bit anxious. Here's what each number means and what to do next. → Blood test guide7 min read Cholesterol blood test explained: what it measures and what your results mean A cholesterol blood test measures the levels of cholesterol in your blood, which is important for assessing heart health. Cholesterol is a fatty substance… → Blood test guide7 min read Vitamin D blood test explained: what it measures and what your results mean A vitamin D blood test measures the level of vitamin D in your blood, which is crucial for bone health and immune function. In the UK, vitamin D levels ar… → HbA1c · Blood sugar7 min read HbA1c blood test explained: what it measures and what your results mean The HbA1c blood test measures your average blood glucose levels over the past two to three months. It's a useful tool for understanding long-term blood su… → Vitamin D · Nutrients7 min read Vitamin D deficiency symptoms explained: what they mean and what to do next Vitamin D deficiency can lead to symptoms like fatigue, bone pain, muscle weakness, and mood changes. These symptoms occur because vitamin D is crucial fo… → Blood test guide7 min read Blood test for blood explained: what it measures and what your results mean A blood test for blood, often called a complete blood count (CBC), measures various components of your blood, such as red blood cells, white blood cells,… → Vitamin D · Nutrients7 min read Understanding Vitamin D Deficiency: Symptoms and What Your Test Results Mean Vitamin D deficiency can lead to a range of symptoms, including fatigue, bone pain, and muscle weakness. These symptoms occur because vitamin D is crucial… → Blood test guide7 min read Blood test explained: what it measures and what your results mean A blood test is a common medical procedure that helps assess your overall health and detect a variety of conditions. It involves taking a small sample of… → Blood test guide7 min read PCOS blood test explained: what it measures and what your results mean Polycystic ovary syndrome (PCOS) is a common condition affecting how a woman's ovaries work, and blood tests can help in understanding it. These tests oft… → CRP · Inflammation7 min read CRP blood test explained: what it measures and what your results mean. A CRP blood test measures the level of C-reactive protein in your blood, which can indicate inflammation in the body. Understanding your CRP levels can he… → Ferritin · Iron7 min read Serum ferritin blood test explained: what it measures and what your results mean. A serum ferritin blood test measures the amount of ferritin in your blood, which indicates your body's iron storage levels. Understanding your ferritin le… → Iron · Blood7 min read Low iron: what it means and what causes it for your health. Low iron can lead to symptoms like fatigue, weakness, and pale skin. This article explains what low iron means, what causes it, and how tracking your leve… → Thyroid · Hormones7 min read Understanding Thyroid Disorders: What Hypothyroidism Means for You Hypothyroidism is a condition where your thyroid gland doesn't produce enough hormones, leading to a range of symptoms. These symptoms can include fatigue… → Vitamin D · Nutrients7 min read Vitamin D deficiency blood test explained: what it measures and what your results mean A vitamin D deficiency blood test measures the level of vitamin D in your blood to assess if you have enough for your body’s needs. Vitamin D is crucial f… → Blood test guide7 min read B12 deficiency symptoms: what your blood test shows. A B12 deficiency can lead to symptoms like fatigue, weakness, and memory problems. A blood test can help identify if your levels are low. Understanding yo… → CRP · Inflammation7 min read CRP blood test explained: what it measures and what your results mean. A CRP blood test measures the level of C-reactive protein in your blood, which can indicate inflammation. This article will help you understand what your… → Ferritin · Iron7 min read Ferritin blood test explained: what it measures and what your results mean. Ferritin levels in your blood indicate how much iron is stored in your body. Understanding your ferritin test results can help you learn about your iron s… → Thyroid · Hormones7 min read Underactive thyroid symptoms: what your blood test reveals. An underactive thyroid, also known as hypothyroidism, can affect your energy levels, weight, and mood. A blood test can help identify if your thyroid is u… → Vitamin D · Nutrients7 min read Vitamin D deficiency symptoms UK: what your blood test shows. Vitamin D deficiency can manifest in various ways, but a blood test is the most reliable method to confirm it. Understanding your vitamin D levels can hel… → Vitamin D · Nutrients7 min read Vitamin D insufficiency: understanding your blood test and what it reveals. Vitamin D insufficiency is a common concern, especially in regions with limited sunlight. A blood test can help determine your vitamin D levels and whethe… → Blood test guide7 min read Blood tests explained: what they measure and what your results mean for your health. Blood tests are a common tool used by healthcare professionals to assess your health. They can measure various components in your blood, providing insight… → Liver · LFTs7 min read Blood tests liver profile explained: what it measures and what your results mean. A liver profile blood test measures various enzymes and proteins to assess liver health. It helps identify potential liver issues by checking levels of su… → Cortisol · Hormones7 min read Your cortisol levels are high — what does it mean? Understanding cortisol and its effects. High cortisol levels can lead to symptoms like increased anxiety, weight gain, and fatigue. These symptoms are common and can result from various non-alar… → HbA1c · Blood sugar7 min read HbA1c blood test explained: what it measures and what your results mean. An HbA1c blood test measures your average blood glucose levels over the past two to three months. It provides insight into how well your body is managing… → Glucose · Blood sugar7 min read Normal blood sugar levels explained: what your test results mean. Normal blood sugar levels indicate how well your body manages glucose, a crucial energy source. Understanding these levels helps you see patterns in your… → TSH · Thyroid7 min read Serum TSH levels explained: what they measure and what your results mean. Serum TSH levels are a key indicator of thyroid function, measured through a blood test. This test evaluates how well your thyroid is working by measuring… → Blood test guide7 min read Fasting blood test explained: what it measures and what your results mean. A fasting blood test checks various components of your blood after you've not eaten for a certain period, usually 8 to 12 hours. This test helps assess yo… → ALT · Liver7 min read Serum alanine aminotransferase level: what your blood test reveals. Serum alanine aminotransferase (ALT) is an enzyme found mainly in the liver, and its levels in your blood can indicate liver health. When you get your blo… → CRP · Inflammation7 min read CRP blood test explained: what it measures and what your results mean for inflammation. A CRP blood test measures the level of C-reactive protein in your blood, which can indicate inflammation in the body. Inflammation can be caused by a vari… → Blood test guide7 min read Polycystic Ovary Syndrome (PCOS) blood test explained: what it measures and what your results mean. A blood test for Polycystic Ovary Syndrome (PCOS) can help identify hormonal imbalances that may contribute to symptoms like irregular periods and unwante… → Blood test guide7 min read Understanding blood types: what they mean and why they matter for your health. Blood types are classified based on the presence or absence of certain antigens on the surface of red blood cells. In the UK, the most common blood groups… → Blood test guide7 min read Full blood count blood test explained: what it measures and what your results mean. A full blood count (FBC) blood test measures various components of your blood, including red and white blood cells and platelets. Understanding your FBC r… → Blood test guide7 min read Full blood count test explained: what it measures and what your results mean. A full blood count (FBC) test measures various components of your blood, including red and white blood cells and platelets. It provides insights into your… →
Beyond the guides

Track the trend, not just today's number.

biomarkr keeps every result in one place, shows what is changing across nine areas of health, and tells you what is worth discussing next. Free for your first year.

Join early access →