Blood tests

This fish is suffering from massive haematemesis which, one the one hand, is very bad news, but on the other hand, makes it very easy to do a blood test.

There are a lot of blood tests. Like, billions. We are going to tell you about the key ones.

Full Blood Count (FBC)

This is common to do. It's pretty much your standard. Especially important to do in infection, heart problems, surgery and anaemia.

• White blood cell (WBC) tells you about of white blood cells per volume of blood. Normal is around 4-11x10. Low means immunosuppression, high means infection or cancer.

White blood cell breakdown: looks at the types of white blood cells present.

• • Neutrophils (40-75%) (raised in bacterial infection)
  • Lymphocytes (20-45%) (raised in viral or bacterial infection, and in haematological cancer)
  • Monocytes
  • Eosinophils
  • Basophils
• Haemoglobin is the amount of Hb in the blood. Normal is around 13-18g/dL in men and 11.5-16g/dL in women. High means dehydration, cancer or lung disease. Low is anaemia: check the page for causes.
• Platelet count is the number of platelets. Normal is around 150-400⁹/L. Low points to cancer, chemo or autoimmune problems, whilst high signifies haematological cancer.
• Mean corpuscular volume (MCV) is a measurement of the average size ⁹/Lof your RBCs. The MCV is elevated when your RBCs are larger than normal (macrocytic), for example in anaemia caused by vitamin_b12 deficiency. When the MCV is decreased, your RBCs are smaller than normal (microcytic), such as is seen in iron deficiency anaemia or thalassaemias.

   * Mean corpuscular haemoglobin (MCH) is a calculation of the amount of oxygen-carrying haemoglobin inside your RBCs. Since macrocytic RBCs are larger than either normal or microcytic RBCs, they would also tend to have higher MCH values. 
   * Mean corpuscular haemoglobin concentration (MCHC) is a calculation of the concentration of haemoglobin inside the RBCs. Decreased MCHC values (hypochromia) are seen in conditions where the haemoglobin is abnormally diluted inside the red cells, such as in iron deficiency anaemia and in thalassaemia. Increased MCHC values (hyperchromia) are seen in conditions where the haemoglobin is abnormally concentrated inside the red cells, such as in hereditary spherocytosis, a relatively rare congenital disorder.