Blood disorders - overview Blood disorders can affect the quantity as well as the function of blood cells or proteins in the blood and affect one or more parts of the blood. Blood disorders can be acute or chronic and be inherited or caused by diseases, medication side effects and a lack of particular dietary nutrients. Blood disorders include: Anaemia – a decrease in red blood cells (RBC). Leukopenia – a decrease in white blood cells (WBC). Thrombocytopenia – a decrease in the number of platelets in the blood increasing the likelihood of bruising and abnormal bleeding. Erythrocytosis – an increase in RBC which can cause thickening of the blood, potential headaches and a red complexion. Leukocytosis – an increase in WBC. Thrombocythemia – an increase in platelets; blood which clots inappropriately can cause thrombosis; and blood can clot excessively which can block blood vessels and potentially cause a transient ischaemic attack. Venous thromboembolism (VTE) – deep vein thrombosis (DVT) which are blood clots that form in a deep vein (lower leg, thigh, pelvis); and pulmonary embolism (PE) is when a clot breaks free and travels to the lungs. Thrombotic thrombocytopenic purpura (TTP) – clots form in small blood vessels which can limit blood flow. This causes increased clotting which decreases the number of platelets available leading to bleeding and bruising. Inherited blood disorders include: Sickle cell disease (also known as sickle cell anaemia) – an inherited disorder which has no cure for most people. It affects haemoglobin (the protein which carries oxygen through the body). Normally RBC are disc-shaped and flexible; however, in sickle cell disease they are crescent-shaped and do not bend or move easily, potentially blocking blood flow. This can lead to serious problems including stroke, eye problems and infections. von Willebrand disease – an inherited bleeding disorder which results in low levels of specific clotting proteins, resulting in abnormal bleeding. Haemophilia – the most common inherited clotting disorder. The blood does not clot due to a deficiency of clotting factors, resulting in bleeding, pain, swelling or tightness in the joints. References Overview of Blood Disorders - Blood Disorders - Merck Manuals Consumer Version Bleeding Disorders - What Are Bleeding Disorders | NHLBI, NIH Sickle Cell Disease - What Is Sickle Cell Disease? | NHLBI, NIH Venous Thromboembolism - What Is Venous Thromboembolism? | NHLBI, NIH von willebrand disease - Search (bing.com) haemophilia - Search (bing.com) Components of Blood - Blood Disorders - Merck Manuals Consumer Version Symptoms of Blood Disorders - Blood Disorders - Merck Manuals Consumer Version