Chronic Lymphocytic Leukaemia

Chronic lymphocytic leukaemia is a type of blood cancer which develops when the body produces too many abnormal white blood cells, known as lymphocytes.

Last modified: February 25, 2022

Quick facts about chronic lymphocytic leukaemiaQuick facts

  • Chronic lymphocytic leukaemia (CLL) starts when the bone marrow produces partly-mature white blood cells that grow and spread abnormally 
  • The white blood cells that CLL affects are called lymphocytes. They move through a large network of tissues and organs called the lymphatic system and impact areas such as the lymph nodes, spleen and liver. Normal lymphocytes mature into B-cells and T-cells, which fight infection
  • Chronic leukaemia develops slowly and may take months or years for symptoms to start showing. Because of this, around 30 to 50% of people diagnosed with CLL never require treatment 
  • CLL is the most common type of chronic leukaemia, with more than 2,200 estimated cases in 2021
  • Almost 80% of CLL cases impact people over 60 years of age

Types of chronic lymphocytic leukaemiaTypes of chronic lymphocytic leukaemia

CLL typically grows slowly, however sometimes CLL can be faster growing. CLL involves a subset of lymphocytes called mature B cells. 


When only the blood and bone marrow is involved, it is known as CLL.


Some patients may only have lymph node and liver or spleen involvement, this is termed Small Lymphocytic Lymphoma (SLL). 

Most patients have a combination of both, which is known as CLL/SLL.

Signs and symptoms of chronic lymphocytic leukaemiaSigns and symptoms

As signs and symptoms for CLL can be similar to other common conditions, it’s important to see your GP or healthcare professional if you experience any of the symptoms below. In many cases, these symptoms may not show for months or years. Discussing anything concerning with your doctor as soon as possible can help give you peace of mind and offer the best chance of successful treatment if you receive a CLL diagnosis.

Although CLL has no symptoms in many cases and is often diagnosed during routine blood tests, symptoms may include:

  • Tiredness

  • Night sweats

  • Repeated infections

  • High temperature

  • Unexplained weight loss 

  • Swollen, painless lymph nodes under the arms, neck or groin

  • Enlarged abdomen and feeling full after eating a small amount

  • Increased bleeding and bruising 

Stages of chronic lymphocytic leukaemiaStages

In Australia, CLL is typically staged using the RAI system. This helps doctors understand what your cancer looks like.

The Binet system is also commonly used.

In general, patients with stage III or IV CLL, or those with rapidly growing lymph nodes, will require treatment. Even if your white blood cell count is very elevated, this alone does not mean that you will need to have treatment.

Stage 0

The patient has lymphocytosis with more than 5×109/L , but no other physical signs.

Stage I

The patient has lymphocytosis and enlarged lymph nodes. The patient does not have an enlarged liver or spleen, anaemia or low levels of platelets.

Stage II

The patient has lymphocytosis and an enlarged spleen and/or liver and may or may not have swollen lymph nodes.

Stage III

The patient has lymphocytosis and anaemia. The patient may or may not have swollen lymph nodes and an enlarged liver or spleen.

Stage IV

The patient has lymphocytosis and low levels of platelets. The patient may or may not have swollen lymph nodes, an enlarged liver or spleen, or anaemia.

Treatment for chronic lymphocytic leukaemia

There are many different types of treatment for chronic lymphocytic leukaemia. Your treatment will depend on you and your cancer.

Frequently asked questions about chronic lymphocytic leukaemia FAQs

Is chronic lymphocytic leukaemia hereditary?

CLL is not usually hereditary. However, there are rare cases where CLL can occur in families due to genetic abnormalities. 

What causes chronic lymphocytic leukaemia?

CLL is caused when changes develop in one or more genes (your DNA). The reason for this is not fully known. However, there are some factors which contribute to the risk of CLL developing, including: 

  • Age – CLL rarely occurs in children
  • Gender – Men are twice as likely to develop CLL than women
  • Gene abnormalities and family history – CLL develops when DNA changes promote cell growth and/or stop cells from dying at the right time. In rare cases, CLL can be passed down in families
  • Exposure to certain chemicals – Radon exposure can increase the risk of CLL
How common is chronic lymphocytic leukaemia?

Leukaemia is less common than other cancer types, affecting 1 in 61 Australians by the age of 85. CLL is the most common type of chronic leukaemia. In 2021 there were over 2,200 cases of CLL, with more males than females diagnosed.


How is chronic lymphocytic leukaemia diagnosed?

There are many different tests that are used to diagnose CLL, alongside a physical examination. This may include blood tests to check your full blood count and determine if leukaemia cells are present.  Some patients may need a lymph node biopsy.  You may need a bone marrow biopsy to check for leukaemia cells within your bone marrow and a CT scan to see which lymph nodes are involved and evaluate the liver and spleen size, although this may not be required at your initial diagnosis.  

What is the difference between chronic lymphocytic leukaemia and chronic myeloid leukaemia (CML)?

CLL and CML are two forms of chronic leukaemia that develop from different types of white blood cells. CLL develops from lymphocytes such as B-cells and T-cells, while CML develops from myeloid cells called granulocytes. 

What can I do to decrease my risk of chronic lymphocytic leukaemia?

There is no known way to prevent CLL. However, there are a number of lifestyle-related factors you can consider to reduce your risk of developing cancer overall, like:

  • Getting regular exercise – Cancer Australia recommends at least 30 minutes of moderate-intensity exercise each day
  • Eating a healthy, balanced diet – Eat a fibre-rich diet from grain and legume sources, as well as enjoy a variety of fruit (2 serves) and vegetables (5 serves) per day, limit your intake of salt, saturated fats, and avoid all processed meat
Are there clinical trials available for chronic lymphocytic leukaemia that I can participate in?

Icon offers clinical trials across a wide range of cancer types and treatments. If you would like more information on participating in a clinical trial, please speak with your doctor who will be able to find a trial that might be right for you and your cancer. 

See current clinical trials delivered by Icon Cancer Centre. 


For a full list of references, click here.
  1. Cancer Council. (2018). Understanding Chronic Leukaemia: A guide for people with cancer,
  2. their families and friends. Retrieved 12 January 2022 from
  3. Leukaemia Foundation. (2020). Chronic lymphocytic leukaemia (CLL). Retrieved 12 January 2022 from
  4. Cancer Council. (2020). Chronic lymphocytic leukaemia (CLL). Retrieved 12 January 2022 from
  6. American Cancer Society. (2018). About Chronic Lymphocytic Leukemia. Retrieved 12 January 2022 from
  7. American Cancer Society. (2018). Causes, Risk Factors, and Prevention. Retrieved 12 January 2022 from
  8. American Society of Clinical Oncology. (2017). Leukemia – Chronic Lymphocytic – CLL: Introduction. Retrieved 12 January 2022 from
  9. Cancer Australia. (2022). Leukaemia in Australia statistics. Retrieved 12 January 2022 from
  10. Australian Institute of Health and Welfare. (2021). Cancer data in Australia: Summary. Retrieved 12 January 2022 from
  11. (2021). Chronic lymphocytic leukaemia (CLL). Retrieved 12 January 2022 from
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