Anaemia Classification and Diagnosis

Severity-Based Classification

The European Society for Medical Oncology (ESMO) classifies anaemia into three categories: mild anaemia (Hb ≤11.9 g/dl and ≥10.0 g/dl), moderate anaemia (Hb ≤9.9 g/dl and ≥8.0 g/dl), and severe anaemia (Hb <8.0 g/dl) 1, 2, 3, 4, 5, 6
The European Society for Medical Oncology (ESMO) recommends using these categories to guide diagnosis and treatment of anaemia 1, 2, 3, 4, 5, 6

Anaemia is defined as haemoglobin concentration below the normal lower limit, which varies by sex, with the World Health Organization (WHO) providing standard definitions: men (Hb <13.0 g/dl), non-pregnant women (Hb <12.0 g/dl), and pregnant women (Hb <11.0 g/dl) 7

The National Cancer Institute Common Toxicity Criteria provides an alternative grading system for cancer patients receiving treatment, with grades ranging from 0 (within normal limits) to 5 (death) 1, 2, 3, 4, 5
The National Cancer Institute (NCI) recommends using this grading system to monitor and manage treatment-related anaemia in cancer patients 1, 2, 3, 4, 5

The European Society for Medical Oncology (ESMO) recommends investigating men with Hb <12 g/dl and postmenopausal women with Hb <10 g/dl more urgently, as lower haemoglobin levels suggest more serious underlying disease 7
The World Health Organization (WHO) suggests that any level of anaemia in the presence of iron deficiency warrants investigation, as even mild anaemia may indicate significant pathology including gastrointestinal malignancy 7

The European Society for Medical Oncology (ESMO) states that anaemia severity directly impacts quality of life and is a major contributor to cancer-related fatigue, making accurate classification clinically important beyond just the numerical value 1, 2, 3, 4, 5, 6

The American Heart Association recommends considering the rate of hemoglobin decline and comorbidities when evaluating anemia symptoms, as patients with heart failure or coronary artery disease may experience worse symptoms at higher hemoglobin levels 8, 9
The American Society of Hematology notes that comorbidities significantly amplify symptoms, and patients with cardiovascular disease may require a lower threshold for transfusion, maintaining Hgb 60-100 g/L 9, 10

Patients with moderate to severe anemia (Hgb 7.0-9.9 g/dL) may experience worsening fatigue and dyspnea, as well as chest pain or angina, especially in those with underlying cardiac disease 8
The American Journal of Hematology reports that patients with critical anemia (Hgb <7.0 g/dL) may experience severe fatigue, marked dyspnea, altered mental status, and hemodynamic instability, with a potential risk of metabolic acidosis, dysrhythmias, seizures, coma, or death 9
The American Journal of Hematology also notes that cyanosis may be present in specific conditions like methemoglobinemia, representing "functional anemia" without actual Hgb decrease 9, 11

The American College of Physicians recommends a lower threshold for transfusion in patients with cardiovascular disease, maintaining Hgb 60-100 g/L 10