What Is Leukemia?

“Leukemia” is the general term for four different types of blood cancer called:
Acute lymphocytic (lymphoblastic) leukemia (ALL)
Acute myelogenous (myeloid) leukemia (AML)
Chronic lymphocytic leukemia (CLL)
Chronic myelogenous leukemia (CML)

It is important to know that how patients are affected and
treated are not the same for each type of leukemia. These four
types of leukemia do have one thing in common – they begin in
a cell in the bone marrow. The cell undergoes a change and
becomes a type of leukemia cell.

The marrow is really two organs in one. The first is the blood
cell-forming organ. This is the site where myelogenous leukemia
begins. The second is the lymphocyte-forming organ and is a
part of the immune system. It is the site where lymphocytic
leukemia begins.

The leukemia is called “lymphocytic” or “lymphoblastic” if the
cancerous change takes place in a type of marrow cell that forms
“lymphocytes.” The leukemia is called “myelogenous” or
“myeloid” if the cell change takes place in a type of marrow cell
that normally goes on to form red cells, some kinds of white cells
and platelets.

The ways in which patients are affected and how they are treated
are different for each type of leukemia.

“Acute lymphocytic leukemia” and “acute myelogenous
leukemia” are each composed of young cells, known as
“lymphoblasts” or “myeloblasts.” These cells are sometimes
called “blasts.” Acute leukemias progress rapidly without
treatment.

“Chronic” leukemias have few or no blast cells. “Chronic
lymphocytic leukemia” and “chronic myelogenous leukemia”
usually progress slowly compared to acute leukemias.

Doctors do not know the causes of most cases of leukemia. They
do know that once the marrow cell undergoes a “leukemic”
change, it multiplies into many cells. These leukemia cells grow
and survive better than normal cells and, over time, they crowd
out normal cells.

The rate at which leukemia progresses and how the cells replace
the normal blood and marrow cells are different with each type
of leukemia.

In acute myelogenous leukemia (AML) and acute lymphocytic
leukemia (ALL), the original acute leukemia cell goes on to
form about a trillion more leukemia cells. These cells are
described as “nonfunctional” because they do not work like
normal cells. They also crowd out the normal cells in the
marrow; in turn, this causes a decrease in the number of new
normal cells made in the marrow. This further results in low red
cell counts (anemia).

In chronic myelogenous leukemia (CML), the leukemia cell
that starts the disease makes blood cells (red cells, white cells
and platelets) that function almost like normal cells. The number
of red cells is usually less than normal, resulting in anemia. But
many white cells and sometimes many platelets are still made.
Even though the white cells are nearly normal in how they work,
their counts are high and continue to rise. This can cause serious
problems if the patient does not get treatment. If untreated, the
white cell count can rise so high that blood flow slows down
and anemia becomes severe.

In chronic lymphocytic leukemia (CLL), the leukemia cell that
starts the disease makes too many lymphocytes that do not
function. These cells replace normal cells in the marrow and
lymph nodes. They interfere with the work of normal
lymphocytes, which weakens the patient’s immune response. The
high number of leukemia cells in the marrow may crowd out
normal blood-forming cells and lead to a low red cell count
(anemia). A very high number of leukemia cells building up in
the marrow also can lead to low white cell (neutrophil) and
platelet counts.

Unlike the other three types of leukemia, some patients with
CLL may have disease that does not progress for a long time.
Some people with CLL have such slight changes that they
remain in good health and do not need treatment for long
periods of time. Most patients require treatment at the time of
diagnosis or soon after.

Types of diabetes

Type 1 diabetes was previously called insulin-dependent diabetes mellitus (IDDM) or juvenile-onset diabetes.
Type 1 diabetes develops when the body's immune system destroys pancreatic beta cells, the only cells in the body that make the hormone insulin that regulates blood glucose.
To survive, people with type 1 diabetes must have insulin delivered by injection or a pump.
This form of diabetes usually strikes children and young adults, although disease
onset can occur at any age.
Type 1 diabetes accounts for 5% to 10% of all diagnosed cases of diabetes.
Risk factors for type 1 diabetes may be autoimmune, genetic, or environmental.
There is no known way to prevent type 1 diabetes.
Several clinical trials of methods of the prevention of type 1 diabetes are currently in progress or are being planned.

Type 2 diabetes was previously called non insulin-dependent diabetes mellitus (NIDDM) or adult-onset diabetes.
Type 2 diabetes accounts for about 90% to 95% of all diagnosed cases of diabetes.
It usually begins as insulin resistance, a disorder in which the cells do not use insulin properly. As the need for insulin rises, the pancreas gradually loses its ability to produce it.
Type 2 diabetes is associated with older age, obesity, family history of diabetes, history of gestational diabetes, impaired glucose metabolism, physical inactivity, and race/ethnicity. African Americans, Hispanic/Latino Americans, American Indians, and some Asian Americans and Native Hawaiians or Other Pacific Islanders are at particularly high risk for type 2 diabetes and its complications.
Clinically-based reports and regional studies suggest that type 2 diabetes in children and adolescents, although still rare, is being diagnosed more frequently, particularly in American Indians, African Americans, and Hispanic/Latino Americans.

Gestational diabetes is a form of glucose intolerance diagnosed in some women during pregnancy.
Gestational diabetes occurs more frequently among African Americans, Hispanic/Latino Americans, and American Indians.
It is also more common among obese women and women with a family history of diabetes. During pregnancy,gestational diabetes requires treatment to normalize maternal blood glucose levels to avoid complications in the infant.
After pregnancy, 5% to 10% of women with gestational diabetes are found to have type 2 diabetes.
Women who have had gestational diabetes have a 20% to 50% chance of developing diabetes in the next 5 10 years.

Other types of diabetes result from specific genetic conditions (such as maturity-onset diabetes of youth), surgery,drugs, malnutrition, infections, and other illnesses.
Such types of diabetes account for 1% to 5% of all diagnosed cases.

What is diabetes?

Diabetes is a condition in which the body either does not produce enough insulin or cannot use insulin properly. Insulin is a naturally occurring hormone in the blood that is necessary for providing our cells with energy to function. Insulin helps sugar (glucose) move from the bloodstream into the cells. When glucose cannot enter our cells, it builds up in the blood (hyperglycemia). This can lead to damage of organs including the eyes and kidneys, or damage of blood vessels and nerves.

Most people with diabetes have “Type 2 diabetes,” which means that the body does not produce enough insulin or the insulin is not able to transfer glucose into cells. Type 2 diabetes used to be known as adult-onset diabetes. In contrast, people with “Type 1 diabetes” (previously called
juvenile-onset diabetes) have a condition where the body does not produce any insulin at all. People with Type 1 diabetes need insulin injections and close monitoring to control their blood sugar levels.