Megaloblastic anemia (patient information)
For the WikiDoc page for this topic, click here
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Amandeep Singh M.D.[2], Omer Kamal, M.D.[3], Lakshmi Gopalakrishnan
Overview
Overview
Megaloblastic anemia is a blood disorder in which there is anemia with larger-than-normal red blood cells.
Anemia is a condition in which the body does not have enough healthy red blood cells. Red blood cells provide oxygen to body tissues.
What are the symptoms of Megaloblastic anemia?
What are the symptoms of Megaloblastic anemia?
- People with mild anemia may have no symptoms, or symptoms may be very mild.
- More typical symptoms of vitamin B12 deficiency anemia include:
- Diarrhea or constipation
- Fatigue, lack of energy, or light-headedness when standing up or with exertion
- Loss of appetite
- Pale skin
- Problems concentrating
- Shortness of breath, mostly during exercise
- Swollen, red tongue or bleeding gums
What causes Megaloblastic anemia?
What causes Megaloblastic anemia?
- Megaloblastic anemia is usually caused by a deficiency of folic acid or vitamin B12.
- Other less common causes are:
- Alcohol abuse
- Certain inherited disorders
- Drugs that affect DNA, such as chemotherapy drugs
- Leukemia
- Myelodysplastic syndrome
- Myelofibrosis
- The anticonvulsant drug dilantin
Who is at highest risk?
Who is at highest risk?
Risk factors relate to the causes.
When to seek urgent medical care?
When to seek urgent medical care?
Call your health care provider if you have any of the symptoms of anemia.
Diagnosis
Diagnosis
- A physical exam may show problems with reflexes or a positive Babinski reflex.
- The following tests may be done:
- Complete blood count
- Reticulocyte count
- Schilling test (if pernicious anemia is suspected)
- Serum LDH
- Serum vitamin B12 level and serum folate levels
- Esophagogastroduodenoscopy (EGD) to examine the stomach, or enteroscopy to examine the small intestine may be done.
- Bone marrow biopsy is done only when the diagnosis is not clear.
Where to find medical care for Megaloblastic anemia?
Where to find medical care for Megaloblastic anemia?
What to expect (Outlook/Prognosis)?
What to expect (Outlook/Prognosis)?
Anemia usually responds well to treatment within 2 months.
Looking for the patient version?
© 2026 MyEClinic – IFTM Institut für Telematik in der Medizin GmbH
