Leukaemia is a form of cancer which can take place in people of all ages, including young children and the elderly. Medically, it is referred to as the cancer of human white blood cells. The disorder is defined by an anomalous increase of undeveloped white blood cells known as blasts.

Generally, it is a disorder in which a group of cells found in the bloodstream become abundant in such a way that they end up endangering a person’s life. In order to understand leukaemia, it is extremely important for one to know the normal functionality of human body.

Classification of Leukaemia

Leukaemia is sub-divided into two large categories, acute and chronic. This sub-division depends on the degree of development of the affected blood cells. Acute leukaemia is defined by a speedy increase in undeveloped blood cells. The increasing abundance of immature blood cells hinders the ability of the bone marrow to yield healthy blood cells. Chronic leukaemia is defined by extreme build-up of developed but atypical white blood cells.

This condition takes months to years to advance, and they are produced at a higher rate than usual. Leukaemia is further sub-divided into lymphocytic leukaemia and myeloid leukaemia based on the type of affected blood cells. Lymphocytic leukaemia is further divided into acute lymphocytic leukaemia and chronic lymphocytic leukaemia. On the other hand, myeloid leukaemia is divided into acute myeloid leukaemia and chronic myeloid leukaemia.

Lymphocytic leukaemia mainly affects the bone marrow that forms lymphocytes which are cells that protect the immune system from infections. Acute lymphocytic leukaemia is defined by excessive production of immature white blood cells known as lymphoblasts. The immature cells mainly affect the bone marrow which results to no production of normal blood cells. Due to this the immune system is unable to fight infections. Hence the patient suffers from easy bleeding due to lack of enough platelets and red blood cells. This type of leukaemia mainly affects young children.

On the other hand chronic lymphocytic leukaemia affects the lymphocytes but gradually develops unlike the acute type. The other difference between the two is the fact that the chronic type mainly occurs in adults and not children. Due to its slow development most patients do not feel the symptoms until the late stages. Accumulation of leukemic cells on the bone marrow and other parts of the body mainly cause anaemia. This may also lead to bruising, infections, easy bleeding and damage of both the red blood cells and platelets.

Acute myeloid leukaemia is the other subtype that is also referred to as granulocytic leukaemia. Generally, it is known to affect myeloid cells which are identified as granulocytes. It causes overproduction of immature myeloid cells known as myeloblasts. That circulates all over the body and blood stream, and may also block blood vessels. This prevents the bone marrow from producing normal blood cells hence poor immunity.

Lastly, there is the chronic myeloid leukaemia which is different from the other types. Since, it has two phases, the slow multiplication stage to the rapid stage. Immature myeloid cells multiply slowly during the first phase for weeks and drastically changes into acute myeloid leukaemia.

Symptoms of Leukaemia

Symptoms of leukaemia are known to develop over a number of weeks, and they can be divided into: bone marrow failure symptoms; systemic symptoms of weight loss, malaise, anorexia and sweat; and local symptoms. Bone marrow failure symptoms are the most common.

Symptoms of Acute Leukaemia

Acute leukaemia starts sharply with extreme symptoms, which turn out to be fatal when left untreated. The early symptoms of acute myeloid and acute lymphocytic leukaemia are similar, and they can easily be mistaken with those of common infectious diseases. The very first symptoms are influenza and fever, and in many cases, these early symptoms to determine the presence of leukaemia may be unclear in children. This presents difficulties as far as early diagnosis of the acute stage of the disease is concerned.

The symptoms are usually produced as multiple occurrences and they have the tendency of crowding the bone marrow. In addition, they disrupt the normal production of blood cells and spilling where they circulate as well as invade vital organs. A large number of acute leukaemia symptoms are caused by a decline in healthy blood cells. Symptoms associated with the decline in red blood cells include but are not limited to: dizziness, headache, paleness, weakness, and fatigue.

Symptoms of Chronic Leukaemia

Chronic leukaemia is known to develop gradually, normally in the absence of symptoms, and may remain unnoticed for an extended period of time. About 25% of chronic lymphocytic leukaemia patients present no symptoms. Eventually, the disease normally is diagnosed as an outcome of a blood test for an unrelated disease or symptom. Patients suffering from chronic lymphocytic leukaemia may show the following symptoms: night sweats, fatigue, loss of appetite, ill health feeling, fever, and lack of energy.

Specific patients may have anaemia, enlarged lymph nodes in the neck, and signs of splenomegaly. On the other hand, common early symptoms of chronic myelogenous leukaemia include: feeling tired, fatigue, weight loss, and a feeling of fullness in the upper abdomen. Other symptoms include bone pain, fever, sweating, and headaches. People with low platelet count show symptoms associated with bleeding. Nonetheless, most chronic myelogenous leukaemia patients present no symptoms during a diagnosis.

Causes of Acute Leukaemia and Chronic Leukaemia

There is no specific cause of leukaemia. Nevertheless, a blend of environmental and genetic factors is involved. Therapeutic and diagnostic irradiation is considered as a possible trigger of leukaemia. Estimates advocate that diagnostic irradiation may account for leukaemia. Factors that have the capacity to magnify the risk of leukaemia include: excessive smoking, exposure to particular chemicals including benzene, genetic history, specific viral infections including T-cell leukaemia virus, and specific blood diseases.

Specific patients with acute leukaemia do present one or more of the known risk factors, including: exposure to hair dyes, smoking, workplace exposure to chemical and petroleum products, and exposure to electromagnetic fields. From the cancer specialists’ point of view, there are no known causes. This is despite the fact that a patient may have one or more of the mentioned risk factors above.

Nonetheless, scientists have made considerable advancements as far as understanding how DNA changes can lead to the formation of leukaemia cells. Most causes of chronic leukaemia are unknown. However, scientists have developed a great understanding of the differences between normal lymphocytes cells, and cells of chronic lymphocytic leukaemia.

References:

1. Leukaemias: http://www.leukaemia.org.au/blood-cancers/leukaemias

2. Leukaemia: http://en.wikipedia.org/wiki/Leukemia

3. Symptoms of Leukaemia: http://www.kidswithcancer.org.au/child-cancers/childhood-leukemia/symp-leuk.html

4. What causes it: http://www.lfq.org.au/disease-information/chronic-leukaemia/chronic-myeloid-leukaemia/what-causes-it