Chronic Lymphocytic Leukemia: Causes, Symptoms, and Treatment
Medically reviewed by Achuta Uppu, MD, Internal Medicine. Last reviewed: October 23, 2026.
What kind of doctor treats Chronic Lymphocytic Leukemia?
A hematologist (a doctor who treats blood diseases) or an oncologist (a cancer doctor) usually treats chronic lymphocytic leukemia. A direct primary care or concierge doctor can be a first stop for an evaluation and can refer you to a specialist when needed.
What is chronic lymphocytic leukemia?
Chronic lymphocytic leukemia, or CLL, is a cancer of white blood cells called lymphocytes. These cells are found in the bone marrow and other parts of the body. Bone marrow is the soft tissue in the center of bones that helps form all blood cells. CLL causes a slow increase in one type of white blood cell, called B lymphocytes or B cells. The cancer cells spread through the blood and bone marrow. CLL can also affect the lymph nodes or other organs such as the liver and spleen.
CLL is one of the most common types of leukemia in adults. It usually gets worse slowly. It often occurs during or after middle age, and it rarely occurs in children. As the number of leukemia cells grows, there is less room for healthy white blood cells, red blood cells, and platelets. This may lead to infection, easy bleeding, and too few red blood cells.
Symptoms
CLL often does not cause symptoms at first. It may be found by blood tests done in people for other reasons. Symptoms usually develop slowly. Later, signs and symptoms may include:
- Painless swelling of the lymph nodes in the neck, underarm, stomach, or groin
- Weakness or feeling tired
- Pain or a feeling of fullness below the ribs
- Fever, and infections that keep coming back
- Easy bruising or bleeding
- Weight loss for no known reason
- Drenching night sweats
- Loss of appetite, or feeling full too quickly
CLL can lead to bleeding from a low platelet count. Platelets are the blood cells that help blood clot. CLL can also lead to other cancers, including a much more aggressive form called Richter transformation.
Causes and who gets it
Doctors do not know what causes CLL. There is no link to radiation exposure. It is unclear if certain chemicals can cause CLL. Exposure to Agent Orange during the Vietnam War has been linked to a slight increased risk of CLL.
CLL usually affects older adults, especially those over age 60. CLL is more common in White people than in people of other races. It is more common in men than in women. Some people with CLL have family members with the disease.
How doctors diagnose it
Your doctor will do a physical exam and ask about your symptoms. Tests that examine the blood are used to diagnose CLL. A complete blood count, or CBC, checks the number of red blood cells, platelets, and white blood cells in a blood sample. Flow cytometry is a lab test that looks at features of cells, such as their size, shape, and markers on the cell surface. FISH is a lab test that looks at and counts genes or chromosomes in cells, and it helps plan treatment.
Treatment
If you have early-stage CLL, your doctor may just monitor you closely. Treatment is not generally given for early-stage CLL unless you have problems such as:
- Infections that keep coming back
- A white cell count that is rapidly getting worse
- Low red blood cell or platelet counts
- Fatigue, loss of appetite, weight loss, or night sweats
- Swollen lymph nodes
Targeted therapy and sometimes chemotherapy are used to treat CLL. Targeted therapy uses drugs or other substances to identify and attack specific cancer cells. Chemotherapy uses drugs to stop the growth of cancer cells, but it is seldom used to treat CLL today. Monoclonal antibodies, which are immune system proteins made in a laboratory, may also be used.
Bone marrow or stem cell transplantation may be used in younger people with advanced or high-risk CLL. A transplant has risks, and it is rarely done today because many other treatments work well. Treatment for CLL may cause side effects. The choice of treatment is made based on test results, your age and general health, and the wish to limit side effects.
When to see a doctor
Contact your doctor if you have enlarged lymph nodes, or unexplained tiredness, bruising, heavy sweating, or weight loss. Also check with your doctor about a fever or infections that keep coming back. Call 911 or go to the emergency room if you have trouble breathing, chest pain, fainting, a sudden change in mental state, or bleeding that will not stop.
How a direct primary care or concierge doctor fits in
A direct primary care doctor charges a flat monthly fee instead of billing insurance, while a concierge doctor usually charges more and often works alongside insurance. Either kind of doctor can do a physical exam, ask about your symptoms, and order blood tests. You can also check with them about a fever or infections that keep coming back.
Common questions
Does everyone with chronic lymphocytic leukemia need treatment right away?
No, not everyone does. If you have early-stage CLL, your doctor may just monitor you closely.
Does radiation cause chronic lymphocytic leukemia?
No, there is no link to radiation exposure. Exposure to Agent Orange during the Vietnam War has been linked to a slight increased risk of CLL. It is unclear if certain chemicals can cause CLL.
Does chronic lymphocytic leukemia run in families?
Sometimes it does. Some people with CLL have family members with the disease. Doctors do not know what causes CLL.
Sources
- MedlinePlus - Chronic lymphocytic leukemia (CLL)
- National Cancer Institute - Chronic Lymphocytic Leukemia Treatment (PDQ), Patient Version
Medical Disclaimer
This content is for general educational and informational purposes only and is not medical advice. It is not a substitute for professional medical advice, diagnosis, or treatment, and reading it does not create a doctor-patient relationship. Always seek the advice of your physician or another qualified health provider with any questions about a medical condition, and never disregard or delay seeking professional advice because of something you read here. If you think you may have a medical emergency, call 911 (or your local emergency number) immediately.
