Merck Manual

Please confirm that you are not located inside the Russian Federation

honeypot link
Quick Facts

Chronic Lymphocytic Leukemia (CLL)

By

The Manual's Editorial Staff

Last full review/revision Jan 2020| Content last modified Jan 2020
Click here for the Professional Version
Get the full details

What is leukemia?

With leukemia, you have a very high white blood cell count. However, the cancerous white blood cells don't work properly, so you're likely to get infections. Those infections may be life-threatening.

Also, the cancerous white blood cells fill up your bone marrow so it can't make normal blood cells such as:

There are many different types of white blood cells but only 2 main types of leukemia:

  • Lymphocytic leukemia: cancer of lymphocytes, which are one type of white blood cell

  • Myelogenous leukemia: cancer of all the other types of white blood cells

Lymphocytic and myelogenous leukemia can be acute or chronic:

  • Acute: cancer of young cells that spreads quickly and can cause death in 3 to 6 months if untreated

  • Chronic: cancer of mature cells that spreads more slowly

What is chronic lymphocytic leukemia (CLL)?

Chronic lymphocytic leukemia (CLL) is a type of white blood cell cancer that affects lymphocytes, which normally help your body fight infections. In CLL, your lymphocytes turn into cancer cells. These cancer cells take the place of healthy lymphocytes in your blood, bone marrow, and lymph nodes (pea-sized organs throughout your body that help fight off infections).

Types of CLL include:

  • B-cell leukemia—this is the most common

  • Hairy cell leukemia

  • T-cell leukemia

What are the symptoms of CLL?

Most people have no symptoms at first.

Later symptoms may include:

You may be more likely to get other cancers, such as skin or lung cancers.

How can doctors tell if I have CLL?

To tell if you have CLL, doctors will:

Sometimes doctors find out that you have CLL when they do blood tests for other health problems.

How do doctors treat CLL?

You may not need any treatment for years.

When you do need treatment, it may include:

Doctors may also give you treatments for your symptoms, including:

NOTE: This is the Consumer Version. DOCTORS: Click here for the Professional Version
Click here for the Professional Version
Others also read

Test your knowledge

Electrical Injuries
Electric currents can cause injuries when they pass through the body. They can burn internal organs and tissues. They can disrupt normal electrical processes such as heart rhythms or nerve impulses. Contact with which of the following electric current sources poses the greatest danger?
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID

Also of Interest

Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
TOP