สาเหตุ อาการ การวินิจฉัย การรักษาโลหิตจาง - Anemia: Causes, Symptoms, Diagnosis, Treatments

Anemia

Anemia is a deficiency in healthy red blood cells and hemoglobin that compromises oxygen delivery throughout the body. Hemoglobin, a crucial component containing iron-rich protein

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Anemia

Anemia is a deficiency in healthy red blood cells and hemoglobin that compromises oxygen delivery throughout the body. Hemoglobin, a crucial component containing iron-rich protein within red blood cells, acts as a courier, carrying oxygen from the lungs to all organs and tissues. Anemia occurs when cells and organs do not receive enough blood to function properly, resulting in symptoms of fatigue, weakness, shortness of breath, pale skin, and jaundice, as well as impaired brain function. Severe anemia can result in heart failure, fainting, and death. Anyone who suspects anemia should seek a doctor's diagnosis to determine the cause and treat the symptoms systematically.

What causes anemia?

Anemia is caused by three main factors, including:

  1. Decreased production of red blood cells and hemoglobin in the body caused by
    • Lack of nutrients necessary for the formation of red blood cells, such as iron, vitamin B12, vitamin B9, or folic acid (folate), which is common in pregnant women
    • Pregnancy: Pregnant women have more lymphatic fluid in their red blood cells than normal, resulting in anemia.
    • Chronic diseases that affect red blood cell production, such as cancer, liver disease, chronic kidney disease, immunodeficiency, HIV infection, and rheumatoid arthritis, impair bone marrow function and result in fewer red blood cells.
    • Bone marrow diseases, such as blood cancer that suppress red blood cell function and production, such as multiple myeloma, leukemia, aplastic anemia, myelodysplastic syndrome, or bone marrow infection.
  2. Hemolysis with an increased rate of red blood cell destruction is commonly due to inherited blood disease but can also be acquired or due to infection, including:
    • Thalassemia is a genetic blood disorder caused by defective hemoglobin synthesis in red blood cells, resulting in fewer red blood cells, a shorter lifespan, and easily broken-down red blood cells.
    • Glucose-6-phosphate dehydrogenase (G6PD) deficiency is caused by a lack of G6PD, an enzyme that normally protects red blood cells from oxidative damage caused by drugs or certain foods such as broad beans, long beans, or mung beans. A lack of the enzyme G6PD results in the depletion of preexisting low intracellular antioxidant glutathione after food exposure, causing rapid intravascular hemolysis with pale skin, tea-colored urine, yellowish skin, or jaundice.
    • Autoimmune hemolytic anemia results from the host's immune system attacking the host's red blood cell membrane antigens, destroying red blood cells.
    • Sickle cell disease (SCD) is an abnormality in the hemoglobin molecules causing abnormal red blood cells to shape that are not biconcave discs with a dimple in the center but instead are shaped like a sickle or a crescent moon, resulting in inefficient oxygen transport to the body and rapid red blood cell turnover.
    • Infections such as Clostridium bacteria, Mycoplasma bacteria, and Plasmodium spp. (the cause of malaria) cause hemolysis and anemia.
  3. Loss of red blood cells from the bloodstream includes acute blood loss, such as aortic aneurysm rupture, hemorrhage from trauma, surgery, or childbirth, or chronic blood loss that later causes iron deficiency, such as heavy menstruation, aortic aneurysm, peptic ulcer, hemorrhoids, or colon cancer.

Anemia Banner 1
Left: Hand of a healthy person     Right: Hand of a person with anemia

What are the symptoms of anemia?

The symptoms of anemia vary depending on the underlying cause and the seriousness of the condition. In its initial stages, anemia might exhibit minimal or no symptoms, then gradually develop more symptoms until the symptoms reach their peak severity. Anemia caused by underlying diseases may manifest symptoms of that disease instead of anemia; as a result, those suffering from anemia are frequently unaware that they have the condition. Anemia can only be confirmed by a doctor after a complete blood count (CBC). The signs and symptoms of anemia are as follows:

  • Dyspnea, shortness of breath, difficulty breathing, inability to take deep breaths.
  • Dizziness, lightheadedness, and a sense of wobbliness while standing or working.
  • Tiredness, weakness, feeling tired easily, and a lack of energy even with minor exertion.
  • Headache caused by iron deficiency or low hemoglobin in red blood cells.
  • Cold hands and feet due to decreased blood circulation in the hands and feet.
  • Fainting and syncope due to a lack of red blood cells carrying oxygen to the brain.
  • Arrhythmia, irregular heartbeat, palpitations, rapid heartbeat, or rhythmic heartbeat
  • Pulsatile tinnitus, hearing a ringing or whistling sound in one ear, alternating back and forth like the sound of cicadas screeching loudly.
  • Pale, yellowish skin or jaundice are prominent symptoms of hemolytic anemia.
  • Chest pain feels like a heavy object pressed or squeezed on the chest, causing tightness.

How is anemia diagnosed?

How is anemia diagnosed?

The hematologist will diagnose anemia by taking a detailed medical history, including family history, and underlying disease, and performing a physical examination, and obtaining laboratory tests, including a complete blood count (CBC). Anemia is defined by hemoglobin levels of less than 13 g/dl in men and less than 12 g/dl in women. Anemia is diagnosed using the following methods:

  • A complete blood count (CBC): The CBC measures the number, size, and shape of red blood cells, as well as the hemoglobin level and hematocrit (Hct%) in red blood cells, white blood cells, and platelets, including the levels of vitamin B12 and vitamin B9 (folate) in whole blood.
  • Peripheral blood smear is a laboratory hematology diagnostic test in which blood drops onto a slide and spreads around. The stained slides will then be examined under a microscope to determine the characteristics of the blood cells and the amount of hemoglobin in the blood.
  • Bone marrow aspiration or biopsy is a laboratory blood test that examines the pathology of the bone marrow by removing a small sample of bone marrow tissue for microscopic examination of its cellular content and composition to diagnose difficult-to-diagnose hematological diseases such as anemia of unknown cause,  leukemia, or aplastic anemia. 

Anemia Banner 4

How is anemia treated?

The hematologist will treat those with anemia individually based on the underlying cause, clinical context, and the severity of the condition, which involve administering iron to support hemoglobin production, conducting blood transfusions, providing injections of biologics to stimulate blood cell production, treating blood diseases, bone marrow diseases, chronic diseases, and other serious ailments identified by the doctor. Anemia treatment options include the following:

  • Iron deficiency anemia: The hematologist will consider giving iron to increase the number and volume of red blood cells. For those who have anemia as a result of significant blood loss, such as hemorrhage, accidents, or internal bleeding. The hematologist may recommend surgery to stop the bleeding as soon as possible.
  • Vitamin deficiency anemia: For those who have anemia due to a lack of vitamin B12, B9, or folic acid, the hematologist may recommend vitamin supplements.
  • Anemia of chronic disease: The hematologist will treat the symptoms by focusing on the type of disease. For those with chronic kidney failure, the hematologist may prescribe Erythropoietin to stimulate red blood cell function.
  • Anemia caused by bone marrow disease: The hematologist will plan treatment based on the underlying disease and the severity of the symptoms, such as medication, chemotherapy, radiotherapy, bone marrow transplant, or stem cell transplant, or stem cell transplant.
  • Aplastic anemia: The hematologist will consider a blood transfusion or a bone marrow transplant to restore the production of healthy blood cells.
  • Hemolytic anemia: The hematologist may recommend immunosuppressants to suppress the immune system and help prevent red blood cell damage while strengthening the body's immunity.
  • Sickle cell anemia: The hematologist will consider treatment options such as giving oxygen, pain relievers, intravenous fluids to reduce pain and prevent complications, blood transfusions, folic acid supplements, and antibiotics.
  • Thalassemia: Thalassemia carriers are asymptomatic or mildly symptomatic and do not require treatment. For those with thalassemia, the hematologist will consider a variety of treatment options based on the severity of the symptoms, such as blood transfusions, folic acid supplements, iron chelation, splenectomy, bone marrow transplant, or stem cell transplant, which is the only known curative treatment for thalassemia.

What are the complications of anemia?

Anemia, if left untreated at an early stage, can lead to complications as the disease progresses. Anemia complications include the following:

  • Severe tiredness
  • Premature birth
  • Arrhythmia
  • Enlarged heart
  • Heart failure
  • Death

What are the preventions of anemia?

  • Anemia due to hereditary, autoimmune, or bone marrow disease should receive treatment as soon as possible.
  • Those with malnourished anemia should eat foods rich in iron, folate, vitamin B12, and vitamin C.
  • Those with anemia of all causes should undergo an annual health check.
  • Over-the-counter medications are not advisable as some can cause ulcers in the stomach and intestines, which can lead to internal organ bleeding.
  • Those who have bloody stools or blotches of bleeding spots on their skin should consult a doctor.
  • Postmenopausal women experiencing vaginal bleeding should seek medical attention.

Foods recommended for anemia.

What foods are recommended for anemia?

Individuals experiencing anemia due to poor nutrition should prioritize supplementing their diet with food sources rich in essential nutrients to support red blood cell production, including:

  • Iron-rich foods include pork, beef, liver, blood, organ meats, egg yolks, shellfish, spinach, kale, gourd, sesame, black beans, and grains.
  • Folate, or vitamin B9, can be found in dark green leafy vegetables like broccoli, spinach, and asparagus, as well as whole grains and legumes.
  • Vitamin B12 includes red meat, fish, eggs, liver, milk, poultry such as chicken, cereals, and grains.
  • Vitamin C includes citrus fruits, berries, broccoli, tomatoes, peppers, and melon.

Anemia, a treatable condition, prolonged treatment can be detrimental

Childhood anemia can be asymptomatic or have only minor symptoms. The severity of anemia symptoms gradually worsens with age, contingent on the underlying cause. Children with severe anemia may experience developmental delays. Anemia in the elderly can lead to heart diseases such as ischemic heart disease, heart arrhythmias, or myocardial infarction, posing life-threatening risks. Children and adults with anemia can be cured if the disease is detected and treated early.

Individuals experiencing persistent fatigue, easy tiredness, or fainting even with minor exertion should seek medical attention for a thorough physical examination. For those suffering from anemia caused by inadequate nutrition, the doctor may recommend iron or vitamin supplements to boost the production of hemoglobin and red blood cells. For individuals with anemia stemming from blood system disorders such as bone marrow diseases or blood cancers, the hematologist will prescribe a comprehensive treatment approach to increase the number of healthy blood cells, prevent complications, and foster an overall stronger and healthier state of physical health and well-being.

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Published: 15 Dec 2023

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