The clinical evaluation of the anemic patient begins with a detailed history and a systematic physical examination, both essential for guiding diagnostic suspicion and properly planning further investigations. Anemia may represent the clinical expression of a wide range of pathological conditions, some of which require urgent intervention.
Medical history
History taking must be accurate and guided by a logical approach aimed at gathering useful elements to distinguish among the different causes of anemia.
It is important to assess:
Onset of symptoms: gradual onset suggests chronic anemia, whereas a rapid onset may indicate acute hemorrhage or massive hemolysis.
Evidence of blood loss: obvious (melena, hematuria, menorrhagia) or occult bleeding must be carefully investigated. Gastrointestinal causes are explored further in the section on iron deficiency anemia.
Medication history: the use of myelotoxic, gastrointestinal-toxic, or immunosuppressive drugs can contribute to anemia development. Drug-induced anemia is addressed in the dedicated section on drug-induced anemia.
Concomitant diseases: chronic inflammatory diseases, renal failure, endocrinopathies, and neoplasms are common causes of normocytic anemia, discussed further in the section on anemia of chronic inflammation.
Family history: a family history of hereditary conditions such as thalassemia or spherocytosis may suggest a genetic cause, explored in the pages on hemoglobin disorders and membranopathies.
It is also essential to investigate possible exposure to environmental or occupational toxins, which may cause aplastic or sideroblastic anemia, as detailed in the respective sections.
Symptoms
Anemia symptoms result from reduced oxygen-carrying capacity and the activation of cardiovascular and respiratory compensatory mechanisms. Their intensity depends both on the rapidity of onset and the severity of hemoglobin reduction.
The main symptoms reported by patients include:
Fatigue, weakness, and reduced exercise tolerance: due to impaired muscle oxygenation.
Dyspnea: especially during exertion, but in severe cases, also at rest.
Palpitations and tachycardia: compensatory mechanisms to maintain adequate cardiac output.
Dizziness, vertigo, or syncope: signs of cerebral hypoperfusion.
Chest pain: in individuals with pre-existing ischemic heart disease, anemia may precipitate angina episodes.
In moderate chronic anemia, symptoms may be subtle or underestimated, while in acute or severe forms, they present rapidly and dramatically. Some specific manifestations related to nutritional deficiencies or hemolysis are analyzed in detail in the dedicated pages.
Physical examination
Physical examination in the anemic patient plays a crucial role in confirming clinical suspicion and orienting etiological assessment. It must be conducted systematically, considering both general signs of tissue hypoxia and specific signs suggestive of the underlying cause.
The most common findings include:
Skin and mucosal pallor: most evident in the conjunctivae, palms, oral mucosa, and nail beds. Its severity correlates with anemia degree but may be less apparent in individuals with darker skin.
Tachycardia and weak pulse: physiological responses to reduced oxygen delivery. Severe cases may also show hypotension and a thready pulse.
Functional systolic murmurs: common in moderate to severe anemia, linked to increased blood flow through heart valves.
Signs of peripheral hypoperfusion: cold hands, acrocyanosis, delayed capillary refill, especially in acute forms.
Beyond general signs, the examination must search for focal manifestations useful for suggesting the anemia's cause:
Jaundice and dark urine: indicative of hemolysis, explored in the section on autoimmune hemolytic anemia and congenital hemolytic disorders.
Splenomegaly or hepatomegaly: suggestive of chronic hematologic diseases, hemolysis, myeloproliferative or infiltrative disorders.
Glossitis, angular cheilitis, brittle nails: suggestive of iron or vitamin deficiency, detailed in the section on nutritional anemias.
Petechiae, ecchymoses, epistaxis: may indicate pancytopenia, as seen in aplastic anemia or myelodysplastic syndromes, covered in the relevant sections.
Signs of heart failure: dependent edema, congestive hepatomegaly, and jugular vein distention may occur in severe chronic anemia.
In elderly patients or those with chronic conditions, anemia may manifest with nonspecific symptoms such as acute delirium, progressive asthenia, falls, or functional decline. Physical examination must therefore also consider geriatric presentation features.
Finally, it is essential to correlate clinical findings with basic blood test results, which represent the next step in the diagnostic work-up. Interpretation of the CBC and red cell indices is covered in the page Interpretation of the CBC.
References
Hoffbrand AV, et al. Clinical manifestations and diagnosis of anemia in adults. Postgrad Med J. 2016;92(1089):264–268.
McPherson RA, Pincus MR. Henry's Clinical Diagnosis and Management by Laboratory Methods. Elsevier. 23rd ed. 2016:527–548.
Kotwal A, et al. Evaluation of anemia in adults: a diagnostic approach. Am Fam Physician. 2020;101(10):601–608.
Green R, et al. Anemia in the elderly: evaluation and management. Blood Rev. 2020;41:100648.
Johnson-Wimbley TD, Graham DY. Diagnosis and management of iron deficiency anemia in the 21st century. Ther Adv Gastroenterol. 2011;4(3):177–184.
Camaschella C. Iron-deficiency anemia. N Engl J Med. 2015;372(19):1832–1843.
Weiss G, Goodnough LT. Anemia of chronic disease. N Engl J Med. 2005;352(10):1011–1023.
Koury MJ, Ponka P. New insights into erythropoiesis: the roles of folate, vitamin B12, and iron. Blood. 2004;104(12):3646–3653.
Guralnik JM, et al. Prevalence of anemia in persons 65 years and older in the United States. Blood. 2004;104(8):2263–2268.
Aronow WS. Anemia in the elderly: etiology and clinical implications. Clin Interv Aging. 2006;1(1):43–50.
