1. Excessive blood loss Aneamia

Chronic bleeding (long-term bleeding) is often undetected for a long time. The patient gradually loses blood, which means a loss of red blood cells and hemoglobin. Acute bleeding (not long term), can also reduce red blood cell count. Excessive blood loss can be caused by

• Stomach ulcers.
• Hemorrhoids
• Inflammation of the stomach (gastritis)
• Cancer - sometimes cancer of the stomach or colon can cause bleeding
• Childbirth - childbirth often involves the loss of blood
• Menstruation - women who have very heavy periods (menorrhagia) have a higher risk of developing anemia
• Surgery
• Trauma which results in bleeding, such as a car accident
• Blood donations - some regular blood donors may develop anemia

2. Excessive red blood cell destruction (hemolysis) Aneamia

A red blood cell usually lives for 110-120 days, after which it breaks down and is removed by the spleen. Some illnesses and conditions cause red blood cells to die too early. When this happens the bone marrow has to make more red blood cells than normal. If the bone marrow cannot keep up with the needed red cell production caused by their early deaths, the red blood cell count will start to fall, leading to hemolysis (anemia caused by excessive red blood cell destruction) The following can cause hemolysis:

• Immune reactions
• Infections
• Some medications
• Toxins (poisons)
• Some medical procedures, such as using a heart-lung bypass machine, or hemodialysis (used by patients with kidney problems)

3. Decreased or deficient red blood cell production Aneamia

In this type of anemia the body either does not produce enough red blood cells, or they may not work properly. People with this type of anemia may have:

• Sickle cell anemia - an inherited disorder which causes the red blood cells to have a crescent shape. The red blood cells break down rapidly, before sufficient oxygen and nutrients can reach vital organs.
• Not enough iron (iron deficiency) - lack of iron is generally caused by poor diet, blood loss, or an inability to absorb sufficient iron from food. Anemia due to iron deficiency among pregnant women who do not take an iron supplement is common.
• Not enough vitamins (vitamin deficiency) - such as vitamin B12, often caused because the stomach cannot produce enough of a substance called intrinsic factor. This intrinsic factor is vital for vitamin B12 to be absorbed from food and drink. People with anemia for this reason have pernicious anemia. The deficiency may be caused by poor diet. A high percentage of older women with anemia are not eating healthily, researchers from Tucson, Arizona, reported in the Journal of the American Dietetic Association (March 2011 issue). They found that anemia in older women was associated with poor consumption of vitamin B12, vitamin C, protein, energy, red meat and folate. They also found that the deficiencies in iron, folate, and vitamin B12 were each linked to a 10% to 20% higher risk of anemia - and a 21% higher risk of chronic anemia. They also found that smoking, BMI (body mass index) and age were linked to anemia risk.
• A high percentage of older women with anemia are not eating healthily, researchers from Tucson, Arizona, reported in the Journal of the American Dietetic Association (March 2011 issue). They found that anemia in older women was associated with poor consumption of vitamin B12, vitamin C, protein, energy, red meat and folate. They also found that the deficiencies in iron, folate, and vitamin B12 were each linked to a 10% to 20% higher risk of anemia - and a 21% higher risk of chronic anemia. They also found that smoking, BMI (body mass index) and age were linked to anemia risk.
• Bone marrow problems - red blood cells are made in the bone marrow. If the bone marrow is faulty it may not be producing enough. This may be caused by a lack of vitamin B12, a serious bone marrow disorder (e.g. leukemia), long term inflammation (e.g. rheumatoid arthritis), or long term infection.
• Some conditions/diseases - people with HIV/AIDS, rheumatoid arthritis, and Crohn's disease may have problems with adequate red blood cell production. Malaria causes anemia in millions of people worldwide. A protein produced by immune cells during malaria infection triggers severe anemia, researchers from Yale University discovered. Patients with chronic kidney disease often have low levels of erythropoietin (a hormone that stimulates the formation of red blood cells) and develop anemia.
• Some medications - especially some cancer medications which are given in combination. These shred healthy red blood cells as they pass through, eventually leading to a whole body shortage of them.