Leukemia is a type of blood cancer that is caused mainly due to an increase in the number of white blood cells in your body. It works by causing abundant malfunctioning white blood cells. It begins in blood-forming tissues, typically in the bone marrow. Leukemia is distinct from other types of cancer that usually originates from organs like lungs, breast, or colon and then spreads to bone marrow. 

Leukemia: Symptoms 

Different types of problems can be noticed by different types of leukemia. Some of the symptoms which you may experience include the following. 

• Headaches 
• Vomiting 
• Fatigue or Weakness
• Swollen lymph nodes 
• Weight loss 
• Fever 
• Shortness of breath 
• Night sweats 
• Bruising 
• Pale skin 
• Pain in joints or bones 
• Frequent nose bleeds
• Severe Infections  

Leukemia: Causes 

The exact cause of leukemia is not known. While the majority of the leukemia forms have no clear cause, some of them are caused due to some recognised triggers. 

Like other cancers, leukemia is caused by DNA mutations. Such mutations can happen naturally or due to artificial and natural ionizing radiation and exposure to certain chemicals such as benzene and alkylating agents in chemotherapy to treat cancer. 

Other causes include smoking, having a family history of leukemia, and having a genetic disorder like Down syndrome. 

Leukemia: Classification 

Leukemia can be classified into two broad categories. First, on how fast it grows and develops, and second, on the type of blood cell involved. 

The first classification i.e. how fast it grows is further split into acute and chronic leukemia.

• Acute leukemia happens due to the overcrowding of immature blood cells which do not carry out normal bodily functions. This results in low haemoglobin and platelets. Such a type of leukemia gets bad very fast, if not treated.
• In Chronic leukemia, some white blood cells are relatively immature but others function normally. The cells fairly look normal but aren’t. They do not serve their very purpose of fighting infections. Normal cells in the bone marrow are crowded out by the leukemia cells which live longer than they should. Chronic leukemia takes time to cause problems. Hence, people live with it for years without even knowing. They are more difficult to cure than acute leukemia.   

The second classification i.e. based on the type of blood cells involved is split into lymphocytic and myelogenous. 

• Lymphocytic (also known as lymphoblastic or lymphoid)  leukemia starts in bone marrow cells which get converted into lymphocytes, a type of white blood cell. 
• Myelogenous (also known as myeloid) leukemia involves the bone marrow cells which create platelets, red blood cells, and different types of white blood cells.

Leukemia: Types 

It can be classified into four main types. 

• Acute Lymphocytic Leukemia (ALL): Most commonly found in young children, ALL can also occur in adults. 
• Acute Myelogenous Leukemia (AML): This type of leukemia is found in both children and adults. 
• Chronic Lymphocytic Leukemia (CLL): With the most common adult leukemia, you may feel well for years. 
• Chronic Myelogenous Leukemia (CML): CML does not have many symptoms for a few months and years. Only people with ages 65+ are more at risk of CML.

Leukemia: Diagnosis 

To diagnose leukemia, your doctor will perform bone marrow and full blood count tests. They might perform the following test. 

• Bone Marrow Biopsy (bone marrow aspiration): 

This test involves removing a small, solid piece of bone marrow, usually from the pelvic bone through a long needle. Such a test is performed to know what type of cancer you have and its severity. 

• Complete Blood Count: 

also known as CBC, the test provides details about platelets, red blood cells, and white blood cells. Lower than normal red blood cells and platelets along with a larger number of white blood cells are detected in case you have leukemia. Some leukemia cells can also be detected which multiply in the bone marrow and spread in the bloodstream.

• Physical examination: 

Your doctor will inquire about the symptoms which you might be experiencing like swollen gums, bruises, tiny skin rashes among other symptoms. In the case of early-stage leukemia, you may not have any obvious symptoms. 

• Imaging examination: 

Tests like CT scan, MRI, chest X-ray might also be performed by your doctor to spot signs of leukemia. 

Leukemia: Treatment

Depending upon the type of leukemia, if it has spread to other tissues, your age, and overall health, there are typically five categories for treating it.

• Chemotherapy: 

It uses drugs to kill the leukemia cells and stop them from splitting. The medicine can be given either as a pill or injected into the bloodstream. 

• Radiation therapy: 

This therapy uses strong energy beams to kill the leukemia cells. It can be given all over the body or at a place where there is a collection of cancer cells. 

• Biologic therapy: 

This therapy makes use of certain drugs to boost the immune system and attack the leukemia cells. 

• Targeted therapy: 

It works by cutting off the specific protein that leukemia cells need to survive or kill them directly.

• Bone marrow transplant: 

This procedure works by killing the cancer cells through chemotherapy and then replacing them with new and healthy cells. 

Conclusion 

Leukemia starts when the DNA of the bone marrow cells does not function normally and mutates. These abnormal cells then spread to the bloodstream. The symptoms include tiredness, weakness, unexplained weight loss, among others. 

It is classified into two main categories, i.e. based on growth and the types of cells involved. There are four types of leukemia, namely Acute lymphocytic leukemia, Chronic lymphocytic leukemia and acute myelogenous leukemia, chronic myelogenous leukemia. 

Leukemia can be diagnosed by conducting a complete blood count, physical examination, bone marrow biopsy, and imaging tests. The treatment depends on various factors such as the type, how far it has spread, and the age factor. Five common treatment categories include chemotherapy, radiation therapy, targeted therapy, biologic therapy, and bone marrow transplant.