Anaemia is a condition where the number of red blood cells or the haemoglobin concentration within the cells is lower than normal .
Blood consists of three types of blood cells :
White blood cells are cells that fight infection
Platelets help the blood to clot
Red blood cells carry oxygen from the lungs in the blood to the vital organs and other tissues
Red blood cells contain haemoglobin, an iron-containing protein that gives blood its red colour. In anaemia, the body produces fewer red blood cells, loses too many of them or these cells are destroyed more quickly than they can be replaced . Haemoglobin is essential in carryng oxygen to the body’s tissues. If there are 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 .
Iron status can be considered as a continuum, from iron deficiency with anaemia, to iron deficiency with no anaemia, to normal iron status with varying amounts of stored iron, and finally to iron overload - which can cause organ damage when severe . Therefore, iron deficiency is the result of long-term negative iron balance. Iron stores in the form of haemosiderin and ferritin are progressively diminished and no longer meet the needs of normal iron turnover . “Iron deficiency is defined as a condition in which there are no mobilizable iron stores and in which signs of a compromised supply of iron to tissues, including the erythron, are noted. The more severe stages of iron deficiency are associated with anaemia” .
Iron deficiency anaemia represents the extreme lower end of the distribution of iron deficiency and therefore should be regarded as a subset of iron deficiency . Since anaemia is the most common indicator used to screen for iron deficiency, the terms anaemia, iron deficiency, and iron deficiency anaemia are sometimes used interchangeably . There are, however, mild-to-moderate forms of iron deficiency in which, although anaemia is absent, tissues are still functionally impaired.
These are some common types of anaemia :
Iron deficiency anaemia: the most common form of anaemia that is caused by a deficiency of iron in the body
Vitamin B12 and folate deficiency anaemia: also known as megaloblastic anaemia
Anaemia of chronic disease: this may be due to cancer, kidney failure, rheumatoid arthritis, Crohn's disease and other chronic inflammatory diseases which interfere with the production of red blood cell .
Aplastic anaemia: a life-threatening type of anaemia caused by a decrease in the bone marrow's ability to produce red blood cells, white blood cells and platelets
Anaemia associated with bone marrow diseases, such as leukaemia
Haemolytic anaemia: this develops when red blood cells are excessively destroyed
Sickle cell anaemia: an inherited form of anaemia which is caused by a defective form of haemoglobin that forces red blood cells to assume an abnormal crescent (sickle) .
The most common causes of anaemia include nutritional deficiencies, particularly iron deficiency, though deficiencies in folate, vitamins B12 and A (inhibition of the normal metabolism of iron) are also important causes . In addition, other causes include haemolysis occurring with malaria; glucose-6-phosphate dehydrogenase deficiency; congenital hereditary defects in haemoglobin synthesis . Blood loss such as that associated with schistosomiasis, hookworm infestation, haemorrhage in childbirth, and trauma, can also result in both iron deficiency and anaemia .
Furthermore, some other common causes of anaemia include haemoglobinopathies and infectious diseasas such as tuberculosis, HIV and parasitic infections .
The pallor of anaemia has been associated with weakness and tiredness long before its cause was known. Now it is recognized that even without anaemia, mild to moderate iron deficiency has adverse functional consequences . “Iron deficiency adversely affects the cognitive performance, behaviour, and physical growth of infants, preschool and school-aged children; the immune status and morbidity from infections of all age groups; and the use of energy sources by muscles and thus the physical capacity and work performance of adolescents and adults of all age groups” . Furthermore, iron deficiency during pregnancy increases perinatal risks for mothers and neonates, and increases overall infant mortality . Moreover, iron-deficient causes altered patterns of hormone production and metabolism. Neurotransmitters and thyroidal hormones which are associated with neurological, muscular, and temperature-regulatory alterations, limit the capacity of individuals exposed to the cold to maintain their body temperature .
Necessary investments in anaemia now as a means to promote human capital development and their nations economic growth and long-term health, wealth and wellbeing by policy makers include :
Improve the identification, measurement and understanding of anaemia among women of reproductive age and scale up coverage of prevention, control and treatment activities
Include required interventions with an effect on anaemia in national health, education, agriculture and development plans as appropriate .
o Addressing nutritional and non-nutritional causes of anaemia and their determinants, as well as nutrition strategies.
Create partnerships between state and non-state actors for financial commitment and a supportive environment for the implementation of comprehensive food and policies
o For nutrition and nutrition-sensitive actions that facilitate prevention and control of anaemia in women of reproductive age 
Ensure development policies and programmes beyond the health sector include nutrition as well as other major causes of anaemia relevant to the country context, specifically the agriculture and education sectors .
Community mobilization and social marketing can be used to raise awareness of the value of iron supplementation in women of reproductive age and other actors involved the supply chain .
Monitor and evaluate the implementation of anaemia control programmes.
Many types of anemia can't be prevented . However, you can avoid iron deficiency anemia and vitamin deficiency anemia by eating a diet that includes a variety of vitamins and minerals, including :
·Iron: Iron-rich foods include beef and other meats, beans, lentils, iron-fortified cereals, dark green leafy vegetables, and dried fruit.
· Folate: This nutrient, and its synthetic form folic acid, can be found in fruits and fruit juices, dark green leafy vegetables, green peas, kidney beans, peanuts, and enriched grain products, such as bread, cereal, pasta and rice .
·Vitamin B-12: Foods rich in vitamin B-12 include meat, dairy products, and fortified cereal and soy products.
· Vitamin C: Foods rich in vitamin C include citrus fruits and juices, peppers, broccoli, tomatoes, melons and strawberries. These also help increase iron absorption .
Some causes of anaemia are more serious than others and it is important to find the reason for anaemia. The treatment of anaemia depends on the underlying cause. For many people this may simply be iron tablets. For others it may be a course of vitamins or other more complex treatments.
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2. Health hub. Anaemia: Types, Symptoms, Diagnosis and Treatment.https://www.healthhub.sg/a-z/diseases-and-conditions/566/anaemia. N.D
3. World Health Organization. Iron Deficiency Anaemia Assessment, Prevention, and Control A guide for programme managers. 1-7. 2001
4. World Health Organization. WHA Global Nutrition Targets 2025: Anaemia Policy Brief. 1-6. 2014
5. Mayo clinic. Anemia. Retrieved from: https://www.mayoclinic.org/diseases- conditions/anemia/symptoms-causes/syc-20351360