Hodgkin’s lymphoma is a type of cancer that starts growing in the white blood cells of the immune system. There are two different types and five subtypes, each with different characteristics.

Lymphocytosis means you have a higher-than-usual lymphocyte count, often defined as more than 3 to 4 billion cells per liter of blood. Lymphocytes are white blood cells that help fight disease. Smudge ...

Chronic lymphocytic leukemia (CLL) affects cells that become lymphocytes. Monitoring the number of lymphocytes in the blood is important for many aspects of this form of cancer. A healthy adult ...

The lymphatic system is the network of vessels, tissues, and organs that are part of the body’s immune system. Lymphoma develops in infection-fighting cells called lymphocytes that circulate through ...

DEAR DR. ROACH: I am a female and almost 75 years old. My vital signs are always normal, and I am active, but slightly overweight. I get quarterly blood draws, and every reading is in the normal range ...