Lymphoma is a form of cancer that affects the immune system - specifically, it is a cancer of immune cells called lymphocytes, a type of white blood cell. There are two broad types of lymphoma and many subtypes.

The two types of lymphoma are described as: Hodgkin's or non-Hodgkin's.

Lymphoma can occur at any age but is the most common cancer in young people. It is often very treatable, and most people live for a long time after being diagnosed.

Lymphoma is cancer of the lymph system (or lymphatic system), which is part of our immunity. It is characterized by the formation of solid tumors in the immune system.1 The cancer affects immune cells called lymphocytes, which are white blood cells.

About 90% of lymphomas are the non-Hodgkin's type while about 10% are Hodgkin's.1

Cancer is a group of over 100 diseases, all of which start with the growth of abnormal cells. Instead of dying in the normal cell life cycle, cancerous cells continue to divide into new abnormal cells, and grow out of control.

Lymphatic cancers are classified by the type of immune cells affected.

In non-Hodgkin's lymphoma, B-cells and T-cells are affected - both being types of lymphocyte white blood cell with special roles in immunity. In the US, B-cell lymphomas are much more common than T-cell ones.

In Hodgkin's lymphoma, the cancer cells are usually an abnormal type of B lymphocyte, named Reed-Sternberg cells. There are many subtypes of Hodgkin's lymphoma, typed by differences seen under the microscope - but a very high percentage of cases are classed as "classic" Hodgkin's.


Leukemia is cancer of the blood cells. Most blood cells form in the bone marrow. In leukemia, cancerous blood cells form and crowd out the healthy blood cells in the bone marrow.

The type of leukemia depends on the type of blood cell that has become cancerous. For example, acute lymphoblastic leukemia is a cancer of the lymphoblasts (white blood cells that fight infection). White blood cells are the most common type of blood cell to become cancer. But red blood cells (cells that carry oxygen from the lungs to the rest of the body) and platelets (cells that clot the blood) may also become cancer.

Leukemia occurs most often in adults older than 55 years, and it is the most common cancer in children younger than 15 years.

Leukemia is either acute or chronic. Acute leukemia is a fast-growing cancer that usually gets worse quickly. Chronic leukemia is a slower-growing cancer that gets worse slowly over time. The treatment and prognosis for leukemia depend on the type of blood cell affected and whether the leukemia is acute or chronic. Chemotherapy is often used to treat leukemia.


Thalassaemia (say "thal-uh-SEE-mee-uh") is an inherited blood disorder that causes your body to make less hemoglobinClick here to see more information. or abnormal hemoglobin. Hemoglobin helps red blood cells spread oxygenClick here to see an illustration. through your body. Low levels of hemoglobin may cause anemiaClick here to see more information., an illness that makes you feel weak and tired. Severe anemia can damage organs and lead to death.

There are two main types: alpha and beta. Beta thalassaemia is the most common.

Beta thalassaemia

You need both alpha- and beta-globin to make hemoglobin. Beta thalassaemia occurs when one or both of the two genes that make beta-globin don't work or only partly work as they should.

  • If you have one damaged gene, you may have mild anemia and probably won't need treatment. This is called beta thalassaemia minor or beta thalassaemia trait. It happens when you get a normal gene from one parent and a thalassaemia gene from the other.
  • When both genes are damaged, it means you got a thalassaemia gene from each parent. You may have moderate or severe anemia.
    • If you have moderate anemia (beta thalassaemia intermedia), you may need blood transfusions.
    • People with severe anemia (called beta thalassaemia major or Cooley's anemia) need blood transfusions throughout life. Symptoms of anemia usually begin within a few months after birth.

Alpha thalassemia

This type occurs when one or more of the four alpha-globin genes that make hemoglobin are missing or damaged.

  • If one gene is missing or damaged: Your red blood cells might be smaller than normal. You will have no symptoms and you will not need treatment. But you are a silent carrier. This means you don't have the disease but can pass the defective gene to your child.
  • If two genes are missing or damaged: You will have very mild anemia that will typically not need treatment. This is called alpha thalassaemia minor or alpha thalassaemia trait.
  • If three genes are missing: You will have mild to moderately severe anemia. This is sometimes called hemoglobin H disease. If it is severe, you may need blood transfusions.
  • If all four genes are missing: This is called alpha thalassaemia major or hydrops fetalis. The fetus will be stillborn, or the child will die soon after birth.

A defect in one or more genesClick here to see more information. causes thalassemia.

If you, either parent, or any of your siblings have thalassemia or carry a gene for thalassemia and you're thinking about having a child, you may want to talk to a genetic counselorClick here to see more information. before you get pregnant. A genetic counselor can tell you how likely it is that your child will have the disease and how severe it might be.


Hemophilia (from the Greek haima meaning blood and philia meaning friend) is an inherited medical condition where the blood does not clot properly. Essentially, hemophiliacs - people with hemophilia - lack a protein called a clotting factor that works with platelets to stop bleeding at the site of an injury. People with hemophilia tend to bleed for longer periods of time after an injury and they are more susceptible to internal bleeding.

There are two major types of hemophilia, labeled type A and type B. Hemophilia A is characterized by a lack of clotting factor VIII (8) and accounts for about 90% of hemophilia cases. Seventy percent of hemophilia A cases are severe. Hemophilia B is characterized by a lack of clotting factor IX (9).

As very rare disorders, hemophilia A occurs about once in every 10,000 births and hemophilia B occurs once in every 50,000 births.

Most cases of hemophilia arise as an inherited disorder, which means that a person is born with hemophilia as determined by his genetic makeup. The condition is caused by a defect in one of the clotting factor genes that lies on the X chromosome.

Hemophilia almost always occurs in males since the gene can be passed from mother to son, and a son lacks a second X chromosome to make up for the defective gene. Girls, on the other hand, are likely to be carriers of hemophilia but unlikely to actually have the disorder. In order to have hemophilia, girls must have the abnormal gene on both X chromosomes - a very rare occurrence.

Though most cases are inherited, it is possible for someone to acquire hemophilia through a spontaneous genetic mutation. It can also develop if the body forms antibodies to clotting factors in the blood that prohibit the clotting factors from working.

Hemophilia symptoms are characterized by excessive bleeding and easy bruising. There may be variation in the severity of these symptoms depending on the deficiency level of the clotting factors. Hemophilia may be suspected in a baby boy if excessive bleeding occurs after circumcision.

Excessive bleeding can occur both externally and internally. Signs of excessive external bleeding include bleeding in the mouth from a cut, bite, or tooth loss, spontaneous nosebleeds, heavy bleeding from a minor cut, and prolonged or continued bleeding after bleeding previously ceased. Signs of excessive internal bleeding include blood in the urine or stool and large, deep bruises. Tightness in joints may be the result of bleeding in the knees, elbows, or other joints, and the joints may become swollen, hot to touch, and painful to move.

Hemophiliacs may develop internal bleeding in the brain from a bump on the head or a more serious injury. Symptoms of brain bleeding include headaches, vomiting, lethargy, behavioral changes, clumsiness, vision problems, and seizures.