Hemoglobinemia (or haemoglobinaemia) is a medical condition in which there is an excess of

hemoglobin Hemoglobin (haemoglobin BrE) (from the Greek word αἷμα, ''haîma'' 'blood' + Latin ''globus'' 'ball, sphere' + ''-in'') (), abbreviated Hb or Hgb, is the iron-containing oxygen-transport metalloprotein present in red blood cells (erythrocyt ...

in the

blood plasma Blood plasma is a light amber-colored liquid component of blood in which blood cells are absent, but contains proteins and other constituents of whole blood in suspension. It makes up about 55% of the body's total blood volume. It is the intr ...

. This is an effect of

intravascular hemolysis Intravascular hemolysis describes hemolysis that happens mainly inside the vasculature. As a result, the contents of the red blood cell are released into the general circulation, leading to hemoglobinemia and increasing the risk of ensuing hyperbili ...

, in which hemoglobin separates from

red blood cells Red blood cells (RBCs), also referred to as red cells, red blood corpuscles (in humans or other animals not having nucleus in red blood cells), haematids, erythroid cells or erythrocytes (from Greek ''erythros'' for "red" and ''kytos'' for "holl ...

, a form of

anemia Anemia or anaemia (British English) is a blood disorder in which the blood has a reduced ability to carry oxygen due to a lower than normal number of red blood cells, or a reduction in the amount of hemoglobin. When anemia comes on slowly, ...

. Hemoglobinemia can be caused by intrinsic or extrinsic factors. When hemoglobinemia is internally caused, it is a result of recessive genetic defects that cause the red blood cells to

lyse Lyse may refer to: * Lyse Abbey, a former Cistercian abbey in Norway * Lyse, an alternative name of Lysebotn, Norway * Lyse Energi, a Norwegian power company * Łyse, Masovian Voivodeship, a village in east-central Poland * Łyse, Podlaskie Voi ...

, letting the hemoglobin spill out of the cell into the blood plasma. In

, hemoglobin is released and binds with

haptoglobin Haptoglobin (abbreviated as Hp) is the protein that in humans is encoded by the ''HP'' gene. In blood plasma, haptoglobin binds with high affinity to ''free'' hemoglobin released from erythrocytes, and thereby inhibits its deleterious oxidat ...

. This causes haptoglobin levels to decrease. Once haptoglobin is saturated, free hemoglobin readily distributes to tissues where it might be exposed to oxidative conditions. In such conditions, heme can be released from ferric hemoglobin. The free heme can then accelerate tissue damage by promoting peroxidative reactions and activation of inflammatory cascades.

Hemopexin Hemopexin (or haemopexin; Hpx; Hx), also known as beta-1B-glycoprotein, is a glycoprotein that in humans is encoded by the ''HPX'' gene and belongs to the hemopexin family of proteins. Hemopexin is the plasma protein with the highest binding affi ...

(Hx) is another plasma glycoprotein able to bind heme with high affinity. Hx sequesters heme in an inert, non-toxic form and transports it to the liver for catabolism and excretion. As long as both haptoglobin and hemopexin are saturated, the remaining free hemoglobins are filtered in the kidney and some of them will be reabsorbed by way of proximal tubules. In externally caused hemoglobinemia, an outside attacker acts as an antibody against the red blood cells. This can cause the cells to be destroyed and their hemoglobin released. In extravascular hemolysis, red blood cells are phagocytized by

macrophages Macrophages (abbreviated as M φ, MΦ or MP) ( el, large eaters, from Greek ''μακρός'' (') = large, ''φαγεῖν'' (') = to eat) are a type of white blood cell of the immune system that engulfs and digests pathogens, such as cancer cell ...

in the spleen and liver. Abnormal value of hemoglobin does not necessarily indicate a medical problem needing treatment. Diet, activity level, medications, a women's

menstrual cycle The menstrual cycle is a series of natural changes in hormone production and the structures of the uterus and ovaries of the female reproductive system that make pregnancy possible. The ovarian cycle controls the production and release of egg ...

, and other considerations can affect the results. Additionally to these, one may have higher than normal hemoglobin if he/she lives in a high altitude area.

Causes

There are other causes besides what happens within the body in the blood cells. Other factors that can cause an excess amount of hemoglobin are: * Smoking (which may result in low blood oxygen levels) * Higher altitudes where your red blood cell production naturally increases to compensate for the lower oxygen supply there Specific disorders or other factors that may cause a high hemoglobin count include: *

Lung disease The lungs are the primary organs of the respiratory system in humans and most other animals, including some snails and a small number of fish. In mammals and most other vertebrates, two lungs are located near the backbone on either side of ...

Heart disease Cardiovascular disease (CVD) is a class of diseases that involve the heart or blood vessels. CVD includes coronary artery diseases (CAD) such as angina and myocardial infarction (commonly known as a heart attack). Other CVDs include stroke, h ...

* COPD (chronic obstructive pulmonary disease) * Dehydration *

Emphysema Emphysema, or pulmonary emphysema, is a lower respiratory tract disease, characterised by air-filled spaces ( pneumatoses) in the lungs, that can vary in size and may be very large. The spaces are caused by the breakdown of the walls of the a ...

* Heart failure * Kidney cancer * Liver cancer * Other types of heart disease * Other types of lung disease *

Polycythemia vera Polycythemia vera is an uncommon myeloproliferative neoplasm (a type of chronic leukemia) in which the bone marrow makes too many red blood cells. It may also result in the overproduction of white blood cells and platelets. Most of the healt ...

, a disorder in which your body makes too many red blood cells. It can cause headaches, fatigue, and shortness of breath.

Diagnosis

Normal hemoglobin levels

Normal hemoglobin levels correlate with the person's age and sex. Levels can vary between different testing systems and under their doctor's consultation. A hemoglobin test measures the amount of hemoglobin in your blood. If a hemoglobin tests shows that a person's levels are below normal, it means they have a low red blood cell count, which is known as anemia. If the test shows higher levels than normal, it means they have hemoglobinemia. The normal range for hemoglobin is: * For men, 13.5 to 17.5 grams per deciliter. 13.5 and 18 g/dl are the lower and upper limits of the acceptable range. * For women, 12.0 to 15.5 grams per deciliter 12 and 16 g/dl are the lower and upper limits of the acceptable range. Symptoms of anemia

Treatment

High hemoglobin levels are a rare occurrence but is usually treated as a symptom for an underlying disease. Consulting a doctor is the best treatment, so they can diagnose your illness and give a recommended treatment plan to lower hemoglobin levels back to normal.

References

* {{cite web, url=http://www.med-ed.virginia.edu/courses/path/innes/rcd/hemo.cfm, title=Hemolytic Anemia, publisher= University of Virginia Health System, accessdate=2009-05-01 Red blood cell disorders Rare diseases

Causes

Diagnosis

Normal hemoglobin levels

Treatment

See also

References