Differential Diagnosis of Anaemia

Iron deficiency anaemia : heavy menstrual , gastrointestinal cancer• The haemoglobin level. Haemoglobin is the iron-rich protein in red blood cells that carries oxygen through the body. The normal range of haemoglobin levels for the general population is 11.1-15.0 g/dL. A low haemoglobin level means a person has anaemia.
• The haematocrit (hee-MAT-oh-crit) level. The normal range for haematocrit levels for the general Red blood cell size. The mean cell volume measures the average size (volume) of red blood cells. In iron-deficiency anaemia, the red blood cells are often smaller than normal.
• A low haematocrit level is another sign of anaemia.
• Serum iron. This test measures the amount of iron in the blood. The level of iron in the blood can be normal even when the total amount of iron in the body is low. For this reason, other iron tests are done.
• Serum ferritin. Ferritin is a protein that helps store iron in the body. Results of this test give doctors a good idea of how much of the body's stored iron has been used up.
• Transferrin level or total iron-binding capacity. Transferrin is a protein that carries iron in the blood. Total iron-binding capacity measures how much of the transferrin in the blood is not carrying iron. People with iron-deficiency anaemia have a high level of transferrin that has no iron.
Gastrointestinal cancer :
One of the first tests ordered is the faecal occult blood test. This test checks the stool for signs of blood. It can detect even small amounts of bleeding anywhere in the intestines. If blood is found in the stool, further tests may be used to find the source of the bleeding, including:
• Colonoscopy. In this test, a thin, flexible tube attached to a video camera is used to examine the rectum and colon for sources of bleeding.
• Upper GI endoscopy. In this test, a thin, flexible tube attached to a video camera is used to examine the stomach and upper intestines. The doctor looks for signs of bleeding.
• Pelvic ultrasound. This test uses sound waves to look at the uterus and other pelvic organs. It checks for causes of heavy vaginal bleeding, such as fibroids.

Vitamin B12 deficiency (pernicious anaemia):• the red blood cells will be the usual colour but larger than normal.
• If the blood test shows a low vitamin B12 count, it must be established whether it is pernicious anaemia or if there is some other cause.
• The Schilling test measures the body's ability to absorb vitamin B12 from the bowel. This will show whether the anaemia is caused by a lack of intrinsic factor.
• Blood tests will also confirm if you have any antibodies to intrinsic factor.


Sickle cell: (haemolytic anaemia)
• Sickle cell anemia is suggested when the abnormal sickle-shaped cells in the blood are identified under a microscope. Testing is typically performed on a smear of blood using a special low-oxygen preparation. This is referred to as a sickle prep.
• Other prep tests can also be used to detect the abnormal hemoglobin S, including solubility tests performed on tubes of blood solutions.
• The disease can be confirmed by specifically quantifying the types of hemoglobin present using a hemoglobin electrophoresis test.The hemoglobin electrophoresis test precisely identifies the hemoglobins in the blood by separating them. The separation of the different hemoglobins is possible because of the unique electrical charges they each have on their protein surfaces, causing them each to move characteristically in an electrical field as tested in the laboratory.

Thalassemia:
• A CBC: People who have thalassemias have fewer healthy red blood cells and less hemoglobin in their blood than normal. People who have alpha or beta thalassemia trait may have smaller than normal red blood cells.
• Hemoglobin tests: People who have thalassemias have problems with the alpha or beta globin protein chains of hemoglobin.
• This involves taking a family medical history and doing blood tests on family members to show whether any have missing or altered hemoglobin genes.

Leukemia:• Blood tests: The lab does a complete blood count to check the number of white blood cells, red blood cells, and platelets. Leukemia causes a very high level of white blood cells. It may also cause low levels of platelets and hemoglobin, which is found inside red blood cells.
• Biopsy: Your doctor removes tissue to look for cancer cells. A biopsy is the only sure way to know whether leukemia cells are in your bone marrow.
• Bone marrow biopsy: The doctor uses a very thick, hollow needle to remove a small piece of bone and bone marrow.The bone marrow is examined under a microscope, where the presence of leukemic cells confirms the suspected diagnosis.
• Genetic studies: The chromosomes of the abnormal cells are examined to look for irregularities. This helps in classifying the various types of leukemia.

Aplastix Anaemia : (eg. Chronic kidney disease)
Doctors diagnose aplastic anemia using blood tests and bone marrow biopsy.
• Blood tests. Normally, red blood cell, white blood cell and platelet levels stay within a certain range. Your doctor may suspect aplastic anemia when all three of these blood cell levels are very low. Many conditions can cause low blood cell counts, but usually of just one type of blood cell. For example, other types of anemia cause a decrease in red blood cells. If you have an infection, your white blood cell count alone may be low.
• Bone marrow biopsy. To confirm a diagnosis, you'll need to undergo a bone marrow biopsy. In this procedure, a doctor uses a needle to remove a small sample of bone marrow from a large bone in your body, such as your hipbone. The bone marrow sample is examined under a microscope to rule out other blood-related diseases. In aplastic anemia, bone marrow contains fewer blood cells than normal. The few cells that are present, however, are normal. In certain diseases such as leukemia and myelodysplastic syndrome, the bone marrow is full of abnormal blood cells.

Chronic kidney disease:• If a person has lost at least half of normal kidney function and has a low hematocrit, the most likely cause of anemia is decreased EPO production.
• The estimate of kidney function, also called the glomerular filtration rate, is based on a blood test that measures creatinine.

Aluminium poisoning

Hypothyroidism : (macrocytic anaemia)
Anemia is often present, usually normocytic-normochromic and of unknown etiology, but it may be hypochromic because of menorrhagia and sometimes macrocytic because of associated pernicious anemia or decreased absorption of folate. Anemia is rarely severe (Hb > 9 g/dL). As the hypometabolic state is corrected, anemia subsides, sometimes requiring 6 to 9 mo.