Red Blood Cells
Red blood cells, or erythrocytes, make up the majority of your blood. They carry oxygen to cells throughout the body and remove carbon dioxide. Red blood cells are produced in the bone marrow, the soft tissue at the center of our bones. A healthy adult produced almost 2.4 million new red blood cells per second. They generally live between 100 and 120 days before being recycled by the body.
Blood disorders involving red blood cells manifest in two ways: a high red-blood cell count or a low red-blood cell count.
High Red Blood Cell Count
There are many conditions that can affect the number of red blood cells your body produces and how long they survive. Too many red blood cells make your blood thicker than usual, which slows down its flow and makes it difficult for your organs to get enough oxygen. It can be caused by:
- The body’s way of compensating for a lack of oxygen (from a change of altitude or certain types of heart and lung disease)
- Excess production of the proteins that stimulate red blood cell production (a common side effect of kidney disease)
- Problems with bone marrow
- Genetic predisposition
Conditions Related to High Red Blood Cell Count
- Polycythemia Vera
Low Red Blood Cell Count
When your blood contains too few red blood cells, you have anemia. There are many types of anemia, based on the cause of your low red blood cell count. Causes of anemia can include:
- Lack of iron from low iron intake or blood loss (common in menstruating women)
- Chronic disease, including kidney disease
- Vitamin B12 deficiency
- Autoimmune disorders
- Bone marrow disorders
- Inherited conditions, including Thalassemia and sickle cell anemia
- Malaria
Conditions Related to Low Red Blood Cell Count
- Iron-deficiency anemia
- Anemia of chronic disease
- Pernicious anemia (Vitamin B12 deficiency)
- Aplastic anemia
- Autoimmune hemolytic anemia
- Thalassemia
- Sickle cell anemia
White Blood Cells
White blood cells, or leukocytes, are the body’s main defense against disease or infection. White blood cells are produced in the bone marrow, the soft tissue at the center of every bone, and live for about 3-4 days. In a healthy adult, they make up only about 1 percent of your total blood supply.
Blood disorders involving white blood cells manifest in two ways: a high white-blood cell count or a low white-blood cell count.
High White Blood Cell Count
An increased white blood cell count is usually an indicator of illness, as your body works fights off infection. However, a white blood cell count that remains high can indicate a disease of the bone marrow or an immune system disorder that affects overall white blood cell production.
- Increased white blood cell counts are a common symptom of cancers such as acute lymphocytic leukemia (ALL) and acute myelogenous leukemia (AML), but they can also be caused by:
- Allergic reactions
- Drug interactions (especially corticosteroids)
- Polycythemia vera (too many red blood cells)
- Rheumatoid arthritis
- Whooping cough
Conditions Related to High White Blood Cell Count
- Leukocytosis
Low White Blood Cell Count
Similarly, a low white blood cell count places you at increased risk of infection or illness, because your body’s natural defenses are lowered. In addition to various forms of leukemia, low white blood cell counts can be caused by:
- Aplastic anemia
- Autoimmune disorders
- Cancer treatment, including chemotherapy and radiation therapy
- HIV/AIDS
- Inherited Disorders
- Lupus
- Medications such as antibiotics and diaretics
- Parasites
- Vitamin deficiencies
Platelets
Platelets, or thrombocytes, are blood cells that promote clotting, so that when you are wounded, your body can stop blood loss. Platelets make up between 5 and 10 percent of your total blood flow.
Blood disorders involving platelets manifest in two ways: a high platelet count or a low platelet count.
High Platelet Count
When your platelet count is too high, your blood can clot inside your body, leading to potentially life-threatening conditions including pulmonary embolism. There are a number of conditions that lead to increased platelet counts, including:
- Acute blood loss
- Chronic kidney disease
- Disorders of the bone marrow
- Heart attack
- Hemolytic anemia
- Inflammation
- Iron-deficiency anemia
- Medication reactions, including epinephrine
- Pancreatitis
- Removal of the spleen
- Trauma
Conditions Related to High Platelet Count
- Essential thrombocythemia and thrombocytosis (production of too many platelets)
- Factor V (Five) Leiden – an inherited condition that causes increased clotting
- Protein C and Protein S deficiencies – inherited conditions that are associated with an increased risk of thrombosis (development of blood clots in the veins) and embolism (a blood clot that travels to the lungs)
Low Platelet Count
Low platelet count can be the result of an inherited disorder such as hemophilia, a side effect of certain medications, or a sign of an immune system disorder.
Conditions Related to Low Platelet Count
- Idiopathic thrombocyopenic purpura (ICP)
- Thrombocyopenic
- Hemophilia
- Von Willebrand disease