Also called: CBC · Complete Blood Count · Hematologic Tests
Important: This page is general information, not medical advice. It does not recommend or prescribe any treatment. Always consult your doctor or pharmacist before starting, stopping or changing any medicine.
About Blood Count Tests
Your blood contains red blood cells (RBC), white blood cells (WBC), and platelets. Blood count tests measure the number and types of cells in your blood. This helps doctors check on your overall health. The tests can also help to diagnose diseases and conditions such as anemia, infections, clotting problems, blood cancers, and immune system disorders.
Specific types include tests for:
- RBC - the numbers, size, and types of RBC in the blood
- WBC - the numbers and types of WBC in the blood
- Platelets - the numbers and size of the platelets
- Hemoglobin - an iron-rich protein in red blood cells that carries oxygen
- Hematocrit - how much space red blood cells take up in your blood
- Reticulocyte count - how many young red blood cells are in your blood
- Mean corpuscular volume (MCV) - the average size of your red blood cells
The complete blood count (CBC) includes most or all of these. The CBC is one of the most common blood tests.
It sits within Blood, Heart and Circulation.
The lead U.S. institute for this subject is the National Heart, Lung, and Blood Institute.
When to speak to someone. Reading about a topic cannot tell you whether it applies to you. Speak to a doctor or pharmacist if symptoms are severe, sudden, getting worse, or simply not going away — and seek emergency care immediately for chest pain, breathing difficulty, sudden weakness or confusion, or a serious allergic reaction.
Research on Blood Count Tests
54 studies areregistered for this condition on ClinicalTrials.gov, the U.S. National Library of Medicine's public registry. A selection is below — the links go straight to the registry entry, not to a summary of ours.
What a registered study does and does not mean. Registration means a study exists and has been declared publicly. It says nothing about whether the treatment being tested works, is safe, or is available to you. Many studies find no benefit — that is what research is for. Never seek out an experimental treatment on the strength of a registry entry alone.
Research currently under way
- CBC Indices and Serum Lactate in Neonatal SepsisAssiut University
- Study to Assess the Impact of the Urine Test Cxbladder Triage Plus on the Number of Cystoscopies Performed on Patients With Invisible Blood in Their Urine.Pacific Edge Limited
- Blood Cell Ratios as Predictors of Response to Platelet-Rich Plasma in Knee OsteoarthritisUtku Gürhan
- Multi-center Validation Study of a Large Language Model-based Intelligent Agent for Blood Cell AnalysisHuashan Hospital
- Assessing Clinical Impact of AI for Iron DeficiencyChina Medical University Hospital
- Diagnosing Asthma With Clinically Accessible, Non-invasive, and Efficient Tests: a Child-inclusive Translational InvestigationUniversité de Sherbrooke
Research already completed
- Relationship Between Periodontal Inflammation Severity and Pan-Immune System Inflammation ValueAbant Izzet Baysal University
- Effects of Exercise and Short Term Rapid Weight Loss on Whole Blood Cells and Lymphocyte Subsets in Highly Trained National Level WrestlersAnkara Yildirim Beyazıt University
- Plasma Molecular Profiling in ALK Inhibitor Resistant NSCLCNational Cancer Centre, Singapore
- Investigation of the Relationship Between Periodontitis and Alzheimer's Disease in Terms of Blood ParametersUskudar University
- Validation of a Non-invasive Hemoglobin Measurement Device in Pregnancy and Postpartum in Kenya, Pakistan, and ZambiaGeorge Washington University
- Reference Intervals of Complete Blood Count and Coagulation Tests in Pregnant Women at Hung Vuong HospitalHung Vuong Hospital
Study data from ClinicalTrials.gov, a service of the U.S. National Library of Medicine. Retrieved 2026-07-30. Registry entries are supplied by study sponsors and investigators; ClinicalTrials.gov does not verify their scientific validity. PocketsInfo is not affiliated with, and not endorsed by, the NLM or the NIH.
Where to read more
Rather than paraphrase, we point you to the primary sources. Every link below is to a government health agency, a national institute or a recognised medical body — grouped by what you are trying to find out.
Start Here
- Blood Tests and UrinalysisBlood Cancer United
- Complete Blood Count (CBC)National Library of Medicine
- What You Need to Know About Blood TestingNational Library of Medicine
Related Issues
- High Red Blood Cell CountMayo Foundation for Medical Education and Research
- Low White Blood Cell CountMayo Foundation for Medical Education and Research
- Overview of White Blood Cell DisordersMerck & Co., Inc.
- Platelet Disorders: MedlinePlus Health TopicNational Library of Medicine
Clinical Trials
- ClinicalTrials.gov: Blood CellsNational Institutes of Health
- ClinicalTrials.gov: Hematologic TestsNational Institutes of Health
Medical subject headings
Clinicians and researchers index this subject under Blood Cell Count. These are the terms to use when searching medical literature.
This page is built from the MedlinePlus health topic record for Blood Count Tests, a service of the U.S. National Library of Medicine (NLM), National Institutes of Health. Information is from MedlinePlus.gov. PocketsInfo is not affiliated with, and is not endorsed by, the NLM or the NIH. Retrieved 30 July 2026.