Pathophysiology of anemia

AMA Citation Bunn H. Bunn H Bunn, H. Franklin.Overview of the Anemias. In: Aster JC, Bunn H. Aster J.C., & Bunn H(Eds.), Eds. Jon C. Aster, and H. Franklin Bunn.eds. Pathophysiology of Blood Disorders, 2e. McGraw Hill; 2016. Accessed June 16, 2023. https://accessmedicine.mhmedical.com/content.aspx?bookid=1900§ionid=137394689 APA Citation Bunn H. Bunn H Bunn, H. Franklin. (2016). Overview of the anemias. Aster JC, Bunn H. Aster J.C., & Bunn H(Eds.), Eds. Jon C. Aster, and H. Franklin Bunn. Pathophysiology of Blood Disorders, 2e. McGraw Hill. https://accessmedicine.mhmedical.com/content.aspx?bookid=1900§ionid=137394689 MLA Citation Bunn H. Bunn H Bunn, H. Franklin. "Overview of the Anemias." Pathophysiology of Blood Disorders, 2e Aster JC, Bunn H. Aster J.C., & Bunn H(Eds.), Eds. Jon C. Aster, and H. Franklin Bunn. McGraw Hill, 2016, https://accessmedicine.mhmedical.com/content.aspx?bookid=1900§ionid=137394689. LEARNING OBJECTIVES After studying this chapter, you should: • Understand how anemia impacts oxygen transport and the ways in which anemic patients compensate for decreased oxygen-carrying capacity. • Develop a coherent approach to the clinical and laboratory evaluation of patients with anemia. • Understand and use classification of anemia based on production versus destruction and on red cell size (mean cell volume). • Be able to explain the phenomenon of ineffective erythropoiesis, including its diagnosis and role in pathogenesis. • Understand the proces...

Anaemia is a condition in which the number of red blood cells or the haemoglobin concentration within them is lower than normal. Haemoglobin is needed to carry oxygen and if you have too few or abnormal red blood cells, or not enough haemoglobin, there will be a decreased capacity of the blood to carry oxygen to the body’s tissues. This results in symptoms such as fatigue, weakness, dizziness and shortness of breath, among others. The optimal haemoglobin concentration required to meet physiologic needs varies by age, sex, elevation of residence, smoking habits and pregnancy status. Anaemia may be caused by several factors: nutrient deficiencies through inadequate diets or inadequate absorption of nutrients, infections (e.g. malaria, parasitic infections, tuberculosis, HIV), inflammation, chronic diseases, gynaecological and obstetric conditions, and inherited red blood cell disorders. The most common nutritional cause of anaemia is iron deficiency, although deficiencies in folate, vitamins B12 and A are also important causes. Anaemia is a serious global public health problem that particularly affects young children, menstruating adolescent girls and women, and pregnant and postpartum women. WHO estimates that 40% of children 6–59 months of age, 37% of pregnant women, and 30% of women 15–49 years of age worldwide are anaemic. Anaemia can cause a range of non-specific symptoms including tiredness, weakness, dizziness or light-headedness, drowsiness, and shortness of breath, ...

Your RBCs contain hemoglobin, an iron-containing protein that carries oxygen throughout your body. When you don’t have enough of these cells, or when they’re not functioning as they should, you can feel low in energy, and you may also have other symptoms, such as feeling cold all the time, headaches, and dizziness. • Malnutrition due to a diet low in vitamin B12, iron, or protein • Gastrointestinal (GI) disease that leads to impaired absorption of dietary nutrients • Rapid bleeding after an injury • Surgical blood loss • Slow, chronic blood loss due to gastrointestinal bleeding, bladder disease, or • Congenital (present at birth) RBC disorders, such as • • Chronic liver or kidney disease • Lead exposure, such as from lead paint or contaminated water • Infections, such as Some of these conditions, like traumatic blood loss, cause sudden and severe anemia. For example, some types of cancer, such as pancreatic cancer, may worsen rapidly, leading to an abrupt onset of anemia. In contrast, lead toxicity or liver disease can progress slowly, leading to a gradual progression of anemia. It is never safe to leave anemia untreated. If you develop any signs of anemia, such as pale skin, headaches, dizziness, or fatigue, you should make an appointment to see a healthcare provider as soon as possible. Blood tests can help Blood tests for anemia include: • • • Further tests may be done to look for the underlying cause. Signs of Severe Anemia Anemia can range in severity. Even mild anemi...