Siamak T. Nabili, MD, MPH
Dr. Nabili received his undergraduate degree from the University of California, San Diego (UCSD), majoring in chemistry and biochemistry. He then completed his graduate degree at the University of California, Los Angeles (UCLA). His graduate training included a specialized fellowship in public health where his research focused on environmental health and health-care delivery and management.
William C. Shiel Jr., MD, FACP, FACR
Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.
In this Article
- Anemia facts*
- What is anemia?
- What causes anemia?
- Can inadequate iron cause anemia?
- What about acute (sudden) blood loss as a cause of anemia?
- What are other causes of anemia?
- Can anemia be hereditary?
- What are the symptoms of anemia?
- How is anemia diagnosed?
- What is a complete blood cell (CBC) count?
- How is blood collected for a complete blood cell (CBC)?
- What is the red blood cell (RBC) count?
- What is hemoglobin?
- What does a low hemoglobin level mean?
- What is the hematocrit?
- How is hematocrit determined?
- How is anemia treated?
- What are the complications of anemia?
- What is the outlook (prognosis) for anemia?
- Blood and Bleeding Disorders FAQs
- Find a local Hematologist in your town
What about acute (sudden) blood loss as a cause of anemia?
Acute blood loss from internal bleeding (as from a bleeding ulcer) or external bleeding (as from trauma) can produce anemia in an amazingly short span of time. This type of anemia could result in severe symptoms and consequences if not addressed promptly. Dizziness, lightheadedness, fatigue, confusion, shortness of breath, and even loss of consciousness can occur with severe, sudden blood loss anemia.
What are other causes of anemia?
Some of the most common causes include:
- Vitamin B12 deficiency may cause pernicious anemia. This type of anemia could happen in people who are unable to absorb vitamin B12 from their intestines due to a number of reasons.
- Strict vegetarians are at risk if they do not take adequate vitamin supplements.
- Long-term alcoholics.
- People who have abnormal structure or function of the stomach or intestines leading to impaired B12 absorption despite adequate intake.
This typically causes macrocytic (large blood cell volume) anemia. Vitamin B12, along with folate, is involved in making the heme molecule that is an integral part of hemoglobin. Folate deficiency can be the culprit of anemia as well. This may also be caused by inadequate absorption, under-consumption of green, leafy vegetables, and also long-term heavy alcohol use.
- There can be rupture or destruction of red blood cells (hemolytic anemia) due to antibodies clinging to the surface of the red cells. Examples of hemolytic anemia include hemolytic disease of the newborn, medication induced hemolytic anemia, transfusion related hemolysis, and autoimmune hemolytic anemia.
- A wide assortment of bone marrow diseases can cause anemia.
- For example, cancers that spread (metastasize) to the bone marrow, or cancers of the bone marrow (such as leukemia or multiple myeloma) can cause the bone marrow to inadequately produce red blood cells, resulting in anemia.
- Certain chemotherapy for cancers can also cause damage to the bone marrow and decrease red blood cell production, resulting in anemia.
- Certain infections may involve the bone marrow and result in bone marrow impairment and anemia.
- Finally, patients with kidney failure may lack the hormone necessary to stimulate normal red blood cell production by the bone marrow.
- Chronic alcohol consumption may lead to anemia via different pathways and thus, anemia is commonly seen in alcoholics.
- Another common cause of anemia is called anemia of chronic disease. This could typically occur in individuals with longstanding chronic diseases.
- Some medications can cause anemia in a variety of ways.
- Human immunodeficiency virus (HIV) and acquired immune deficiency syndrome (AIDS) can cause anemia.
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