Anaemia is associated with increased cardiovascular morbidity and mortality as well as decreased quality of life^{12, 13, 14, 15}. The symptoms of anaemia vary according to the type of anaemia and the underlying cause.

Symptoms common to many types of anaemia include the following:

• Fatigue or lack of energy
• Poor concentration ability
• Dizziness
• Headaches
• Pallor (pale skin)
• Shortness of breath
• Cramps
• Rapid heartbeat (tachycardia)

Multiple symptoms of anaemia 

 

Frequently, anaemia can be detected through routine blood tests before symptoms are apparent; it is diagnosed by laboratory determinations of haemoglobin serum levels (Hb, the amount of haemoglobin in the blood, expressed in grams per decilitre) and the corresponding haematocrit value (HCT, the fraction in percent of whole blood volume that consists of red blood cells). Further helpful parameters of differential diagnostic value can be the mean corpuscular volume (MCV, the average volume of the red cells), the mean corpuscular haemoglobin (MCH, the average amount of haemoglobin per red blood cell), the mean corpuscular haemoglobin concentration (MCHC, the average concentration of haemoglobin in the cells), and the total red blood cells (number of RBCs).

Determination of the haematocrit (HCT) by means of centrifugation (separation of the blood components from each other) 

 

As said above, haemoglobin is an oxygen-carrying protein complex inside the RBCs that integrates elemental iron for reversible oxygen binding. The assessment of haemoglobin concentration is a standard measurement in laboratory blood testing which evaluates the number of RBCs per fixed volume of blood. Levels below normal are an indicator for anaemia.

The normal level of haemoglobin differs between males and females. According to the World Health Organization (WHO), for adult men anaemia is typically defined as a haemoglobin level of less than 13.0 g/dL, and for adult, non-pregnant women, as a haemoglobin level of less than 12.0 g/dL.¹⁶ The second parameter for anaemia assessment, the haematocrit, is the percentage value of RBCs in the total blood volume.

Table 1 presents the anaemic ranges of Hb and HCT values (note that these are general values and are not specific for patients with a particular condition, including chronic kidney disease).^{16, 17} Additional laboratory tests are needed to diagnose and to differentiate between the various forms of anaemia.

*General values, not specific for patients with a particular condition, including chronic kidney disease.

For the specific circumstances applicable to CKD patients, haemoglobin and HCT levels alone are not sufficient to diagnose iron deficiency anaemia (IDA), which is defined as meeting the criteria for both iron deficiency and anaemia based on haemoglobin testing.