What Is Anemia? What Causes Anemia?

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Main Category: Blood / Hematology
Also Included In: Urology / Nephrology
Article Date: 25 Jul 2009 - 0:00 PDT

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When the number of red blood cells or concentrations of hemoglobin are low a person is said to have anemia. Hemoglobin is a protein (metalloprotein) inside the red blood cells that contains iron and transports oxygen.

Anemia is the most common disorder of the blood. Approximately 3.5 million Americans are affected by it. It is much more common in developing countries, especially in very poor areas where people suffer from malnutrition. In many parts of Africa severe anemia is also caused by Malaria.

As many people who become infected with Malaria already have pre-existing anemia, most commonly due to malnutrition and helminthiasis (a disease caused by a parasitic worm), the problem is compounded.

There are hundreds of types of anemia, which is divided into three groups:

Excessive blood loss anemia

Chronic bleeding (long-term bleeding) is often undetected for a long time. The patient gradually loses blood, which means a loss of red blood cells and hemoglobin. Acute bleeding (not long term), can also reduce red blood cell count. Excessive blood loss can be caused by:

• Stomach ulcers.


• Hemorrhoids.


• Inflammation of the stomach (gastritis).


• Cancer - sometimes cancer of the stomach or colon can cause bleeding.


• Some medications - NSAIDS (nonsteroidal anti-inflammatory drugs) if used for prolonged periods, or in high doses, can occasionally cause stomach bleeding.


• Childbirth - childbirth often involves the loss of blood.


• Menstruation - women who have very heavy periods (menorrhagia) have a higher risk of developing anemia.


• Surgery


• Trauma which results in bleeding, such as a car accident.


• Blood donations - some regular blood donors may develop anemia.

Excessive red blood cell destruction (hemolysis) anemia

A red blood cell usually lives for 110-120 days, after which it breaks down and is removed by the spleen. Some illnesses and conditions cause red blood cells to die too early. When this happens the bone marrow has to make more red blood cells than normal. If the bone marrow cannot keep up with the needed red cell production caused by their early deaths, the red blood cell count will start to fall, leading to hemolysis (anemia caused by excessive red blood cell destruction)

The following can cause hemolysis:

• Immune reactions
• Infections
• Some medications
• Toxins (poisons)
• Some medical procedures, such as using a heart-lung bypass machine, or hemodialysis (used by patients with kidney problems)

Decreased or deficient red blood cell production anemia

In this type of anemia the body either does not produce enough red blood cells, or they may not work properly. People with this type of anemia may have:

• Sickle cell anemia - an inherited disorder which causes the red blood cells to have a crescent shape. The red blood cells break down rapidly, before sufficient oxygen and nutrients can reach vital organs.


• Not enough iron (iron deficiency) - lack of iron is generally caused by poor diet, blood loss, or an inability to absorb sufficient iron from food. Anemia due to iron deficiency among pregnant women who do not take an iron supplement is common.


• Not enough vitamins (vitamin deficiency) - such as vitamin B12, often caused because the stomach cannot produce enough of a substance called intrinsic factor. This intrinsic factor is vital for vitamin B12 to be absorbed from food and drink. People with anemia for this reason have pernicious anemia. The deficiency may be caused by poor diet.


• Bone marrow problems - red blood cells are made in the bone marrow. If the bone marrow is faulty it may not be producing enough. This may be caused by a lack of vitamin B12, a serious bone marrow disorder (e.g. leukemia), long term inflammation (e.g. rheumatoid arthritis), or long term infection.


• Some conditions/diseases - people with HIV/AIDS, rheumatoid arthritis, and Crohn's disease may have problems with adequate red blood cell production. Malaria causes anemia in millions of people worldwide. A protein produced by immune cells during malaria infection triggers severe anemia, researchers from Yale University discovered. Patients with chronic kidney disease often have low levels of erythropoietin (a hormone that stimulates the formation of red blood cells) and develop anemia. A study published by the Canadian Medical Association Journal reported that anemia may be beneficial to patients with inflammatory disease, and advocate restraint in treating mild to moderate forms of anemia.


• Some medications - especially some cancer medications which are given in combination. A cancer drug, Avastin, given in combination with Sutent, is linked to microangiopathic hemolytic anemia, which is caused by by a build up of platelets and other organic obstructions on the inner walls of very small blood vessels. These shred healthy red blood cells as they pass through, eventually leading to a whole body shortage of them.

What are the symptoms of anemia?

People whose anemia develops gradually may have no symptoms for a long time. If it develops rapidly symptoms will usually be felt much sooner. Symptoms will vary according to the type of anemia, its underlying cause, and if there are any underlying health problems.

Below are some symptoms linked to anemia - tiredness and lethargy are the most common ones: Lethargy is a mental state while fatigue is a physical state. Lethargy may or may not be associated with physical symptoms. If somebody suffers from fatigue - is physically tired - it is not uncommon for his/her mental state to be affected as well.

• Fatigue (tiredness)
• Lethargy - sluggishness, apathy, a feeling of laziness
• Malaise - a vague feeling that one is not well
• Dyspnea - shortness of breath; difficult or labored breathing
• Poor concentration
• Palpitations - unpleasant irregular and/or forceful beating of the heart
• Sensitivity to cold temperatures

The following symptoms are possible, but less common

• Tinnitus (ringing in the ears)
• Headache
• Sense of taste is affected
• Sore tongue
• Dysphagia - difficulty is swallowing
• Pallor (pale complexion)
• Atrophic glossitis - very smooth tongue
• Dry and flaky nails
• Angular chelosis - ulcers in the corner of the mouth
• Restless leg syndrome - this is more common among patients with iron deficiency anemia

The following symptoms are possible, but extremely rare

• Swelling of the legs and/or arms
• Chronic heartburn
• Vomiting
• Increased sweating
• Blood in stools (feces)

How is anemia diagnosed?

A GP (general practitioner, primary care physician) will probably carry out a physical examination, order a blood test, and ask the patient some questions.

• Blood test
  
  A blood test will measure the patient's red blood count and levels of hemoglobin. If the levels are low the patient has anemia. The blood test will also reveal whether the blood cells have an unusual shape, color or size. Patients with iron deficiency have smaller and paler red blood cells compared to healthy individuals. A patient with a vitamin deficiency will have fewer and larger red blood cells.
  
  Adults should have hematocrit values (red blood cell count) between 32% and 43%, and hemoglobin values from 11 to 15 grams per deciliter.


• Some questions the doctor may ask
  
  The doctor will also try to find out what may be causing or contributing to the anemia by asking:
  
  
  • Diet - what the patient eats, and whether his/her diet includes enough vitamins and minerals, - especially iron and vitamin B12.
  
  
  • Medications - what drugs the patient has been taking, how often, for how long, and what doses.
  
  
  • Menstruation - whether periods are heavy (menorrhagia) and whether heavy periods have been happening for a long time.
  
  
  • Family history - whether any close relatives have/had anemia, blood disorders, or gastrointestinal bleedin/g. A close relative is usually limited to siblings and parents.
  
  
  • Medical history - whether the patient has a chronic disease.
  
  
  • Blood donation - whether the patient is a regular blood donor.
  
  
• Physical examination
  
  
  • Rectal examination - a doctor may carry out a rectal examination to determine whether something in the gastrointestinal tract may be causing bleeding. GPs are used to doing this kind of examination. If an abnormality is detected the GP will refer the patient to a specialist (gastroenterologist).
  
  
  • Pelvic examination - if the GP suspects heavy menstrual bleeding may be causing the anemia he/she may carry out a pelvic examination. If the patient does not respond to iron supplement treatment and has heavy periods the GP may refer her to a gynecologist.

What is the treatment for anemia?

• Iron deficiency - the GP will prescribe an iron supplement to restore body levels of iron. An example is ferrous sulphate, which is taken orally up to three times daily. Side effects, which are rare, may include diarrhea, constipation, stomach upset, and heartburn. Patients who find ferrous sulphate unsuitable may be given ferrous gluconate, which is less likely to have side effects but takes longer to work.


• Diet - patient's whose diets are found to be lacking in iron will be encouraged to consume plenty of iron-rich foods, such as dark-green leafy vegetables, artichokes, apricots, beans, lentils, chick peas, soybeans, meat, nuts, prunes, and raisins.


• Underlying causes - if there is an underlying cause for the anemia this must be treated. If non-steroidal anti-inflammatory drugs (NSAIDs) are found to be a contributory factor the doctor will prescribe an alternative medication.

The doctor will ask the patient to return a few weeks later to check that the treatment is working. If treatment has not worked the doctor will try to find out whether any undesirable side-effects may have made the patient stop taking the iron supplements.

What are the complications of anemia?

• Pregnancy
  
  Pregnant women who are severely anemic have a significant risk of complications, especially when they give birth and afterwards. Giving birth often involves losing blood; being anemic already and then losing blood can result in serious complications. If a mother is severely anemic her baby is much more likely to be born prematurely and underweight. Babies born to mothers with anemia are much more likely to have problems with anemia themselves later on in infancy.


• Fatigue
  
  Fatigue may have a considerable impact on the quality of life of the patient. If the anemia is severe the patient may feel too tired to work, or carry out essential daily tasks. Long-term fatigue may eventually lead to clinical depression.
  
  Researchers from Wake Forest University Baptist Medical Center found that elderly people with anemia have more disabilities and score lower on physical performance and strength tests than those without anemia.


• Susceptibility to illness and infection
  
  People with untreated anemia are more susceptible to illness and infection, compared to healthy people.


• Heart Problems
  
  The heart needs to pump more blood to make up for the lack of oxygen and nutrients if you are anemic. This can eventually lead to congestive heart failure.
  
  Researchers from Charles Sturt University found that the presence of anemia in patients with chronic heart failure is associated with a significantly increased risk of death.


• Nerve damage
  
  Lack of vitamin B-12, one of the causes of anemia, can result in nerve damage. Good nerve function requires an adequate supply of vitamin B-12.

Written by Christian Nordqvist


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