The severity of signs and symptoms related to anemia depends on several factors: the rate of development of anemia (acute vs chronic), the extent of anemia that is present, the age and general physical condition of the patient, and other existing comorbidities. Children and young adults, for example, may tolerate a significant decline in RBC volume with minimally altered vital signs until they become acutely hypotensive, whereas elderly patients frequently have other comorbidities that make physiologic compensation challenging.3,4 Patients with chronic and slowly developing anemia may have no complaints even with hemoglobin levels as low as 5 to 6 grams/dL. Typically, most otherwise healthy adults will be symptomatic when hemoglobin levels decrease to about 7 grams/dL.
Patients with chronic anemia may note weakness, fatigue, dizziness, lethargy, dyspnea with minimal exertion, palpitations, and orthostatic symptoms. Specific historical features can be helpful in the identification and diagnosis of anemia; a history of recent trauma, hematochezia, melena, hemoptysis, hematemesis, hematuria, or menorrhagia suggests possible anemia. More subtle historical features include relevant comorbidities such as peptic ulcer disease, chronic liver disease, and chronic renal disease. Specific inquiries about the use of antiplatelet agents, anticoagulants, and nonsteroidal anti-inflammatory agents should be made.
Physical exam findings that may be present in patients with clinically significant anemia include tachycardia; skin, nail bed, and mucosal pallor; systolic ejection murmur; bounding pulse; and widened pulse pressure (Figure 231-1). Signs of easy bleeding or bruising suggest a coagulation disorder. Evidence of jaundice and hepatosplenomegaly suggests hemolysis. Unusual skin ulcerations, peripheral neuropathy, or neurologic signs such as ataxia or altered mental status may be evidence of nutritional deficiencies. Additional manifestations may depend on comorbid illnesses. For example, a patient with preexisting angina may find that episodes of chest pain are markedly worsened when anemia is present.
Pale conjunctiva (A) and palms (B) in patient with anemia. In B, the physician's hand is on the left for comparison with the patient's hand on the right. [Image used with permission of J. Stephan Stapczynski, MD.]
Patients who develop an acute, severe anemia may have all the signs and symptoms noted above and, in addition, may have hypotension, resting and exertional dyspnea, palpitations, diaphoresis, anxiety, or severe weakness that may progress to lethargy and altered mental status. They may also complain of thirst and will usually have decreased urine output. Loss of >40% of blood volume from trauma or spontaneous hemorrhage can lead to severe symptoms that are due more to intravascular volume depletion than to anemia.10 In healthy patients, myocardial oxygen delivery usually is not limited until hemoglobin concentration is 50% or less of normal.