Symptomatic Anemia occurs when it develops  rapidly or becomes profound:
  • Symptoms: Dyspnea on Exertion; Headache; Malaise; Angina
  • Causes: Bleed (incl. occult GI/Pelvic); Hemolysis; B12 Deficiency
Signs: Usually none.
  • Pale Conjunctive:  Hgb <8 gm
  • Frank Pallor:  Hgb <6 gm
Diagnosis easy:   CBC
  • MCV Normocytic (80-100) in acute bleed
  • Microcytosis (iron deficiency from blood loss) may not develop for several weeks from acute bleed
  • Chronic Anemia:  Differential Dx as per the MCV
If very acute bleed, Hgb & Hct may be completely normal
  • body needs time to hemodilute from extravascular space
  • In ER setting, run 1-2 L  Normal Saline & repeat the H&H

See postings Anemia-1 (Intro); Anemia-2 (Microcytic); Anemia-3 (Macrocytic & Normocytic)