A Full Blood Count (FBC), also called a Complete Blood Count (CBC) or hemogram, is one of the most common blood tests used to give a broad picture of your overall health. It measures the main types of cells circulating in your blood: red blood cells (RBCs), white blood cells (WBCs), and platelets. Because it checks multiple components at once, it can help detect problems such as anemia, infection, inflammation, and blood-clotting issues.

An FBC/CBC typically includes:

Red blood cell measures (often including RBC count, hemoglobin, hematocrit, and red cell indices such as MCV, MCH, and MCHC). These values help show how well your blood carries oxygen. For example, low hemoglobin/hematocrit commonly suggests anemia (which can be related to iron, B12, or folate deficiency, blood loss, or chronic disease). High hemoglobin/hematocrit may occur with dehydration, lung disease, living at high altitude, or certain bone marrow conditions.

White blood cell count and differential (neutrophils, lymphocytes, monocytes, eosinophils, basophils). WBCs are part of your immune system. High WBC can be seen with infections, inflammation, physical stress, or some blood disorders. Low WBC can occur with certain viral infections, autoimmune conditions, bone marrow suppression, or as a side effect of some medications (including some chemotherapy and immune-suppressing drugs).

Platelet count (and sometimes platelet size measures like MPV). Platelets help your blood clot. Low platelets can increase the risk of bruising or bleeding, while high platelets can be reactive (for example, due to inflammation or iron deficiency) or less commonly related to a bone marrow disorder.

FBC/CBC results are interpreted together with your symptoms, medical history, medications, and other tests. A single “out of range” value does not always mean disease—mild changes can happen due to dehydration, recent illness, pregnancy, altitude, smoking, or normal biological variation. Your clinician will look for patterns (for example, anemia plus low MCV suggesting possible iron deficiency) and decide whether repeat testing or further investigation is needed.

A Full Blood Count is often ordered as part of a routine health check or when a doctor needs clues about the cause of symptoms. It may be used to screen for common problems, diagnose conditions, and monitor ongoing illness or treatment.

Common reasons your clinician may request a complete blood count (hemogram) include:

Symptoms that may suggest anemia or low oxygen-carrying capacity, such as tiredness, weakness, shortness of breath, dizziness, headaches, pale skin, or reduced exercise tolerance.

Symptoms of infection or inflammation, such as fever, chills, body aches, sore throat, persistent cough, or feeling generally unwell.

Easy bruising or bleeding, including frequent nosebleeds, bleeding gums, heavy menstrual bleeding, tiny red/purple spots on the skin (petechiae), or prolonged bleeding after cuts—possible signs of platelet problems.

Unexplained weight loss, night sweats, swollen lymph nodes, or recurrent infections, where the white blood cell count and differential may provide important clues.

Monitoring known conditions such as anemia, chronic kidney disease, inflammatory diseases, or blood disorders, to see if they are stable, improving, or worsening.

Checking for medication effects. Many medicines can affect blood counts (for example, some antibiotics, anti-seizure medications, immunosuppressants, and chemotherapy). A CBC can help detect low white cells, low platelets, or anemia early.

Pre-operative assessment or before certain procedures, to confirm adequate hemoglobin (oxygen-carrying capacity) and platelet levels (clotting ability).

General wellness screening during an annual physical or when establishing a baseline for future comparisons.

• Anemia (including iron-deficiency anemia, vitamin B12/folate deficiency anemia, anemia of chronic disease)

• Acute and chronic infections (bacterial or viral)

• Inflammatory and autoimmune disorders (e.g., rheumatoid arthritis, lupus)

• Thrombocytopenia (low platelets) and thrombocytosis (high platelets)

• Bleeding disorders and clotting-related conditions (as suggested by platelet abnormalities)

• Leukemia and other bone marrow disorders (e.g., myeloproliferative neoplasms)

• Neutropenia or lymphopenia (low specific white blood cell types, from various causes)

• Chronic kidney disease (often associated with anemia)

• Nutritional deficiencies (iron, vitamin B12, folate)

• General health screening and establishing a baseline complete blood count (CBC/hemogram)

• Improving energy levels by identifying anemia or nutrient-related causes of fatigue

• Supporting immune health by checking for signs of infection or low white blood cells

• Monitoring inflammation or recovery after illness

• Assessing bleeding/bruising tendency through platelet count monitoring

• Tracking treatment safety and side effects for medications that can affect blood counts

• Pre-surgery or pre-procedure readiness (ensuring adequate hemoglobin and platelets)

• Long-term monitoring of chronic conditions such as kidney disease or autoimmune disorders