Lymphocytes (Absolute)
The actual number of lymphocytes, immune cells that help fight viruses and remember germs, in a given amount of blood.
AI-verified against cited sources. Awaiting expert reviewAlso called ALC, Lymph#, LYM#LOINC 731-0
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What it is
Lymphocytes are a type of white blood cell. The main kinds are T cells, B cells and natural killer (NK) cells, and they help your body fight infections and remember germs it has met before. The absolute lymphocyte count is the actual number of these cells in a small amount of blood. It comes from the CBC with differential. Lymphocyte subsets such as CD4 and CD8 are separate tests.
Why it matters
Because it is a real count, it is more reliable than the percent version, which shifts whenever another white cell type changes. Counts move during infections, after stress or hard exercise, and with some medicines, and most of these shifts settle on their own. A count that stays outside the usual range is worth a conversation, with your other blood counts and symptoms in mind.
If it’s low
A low count (lymphopenia) is common and is often temporary, for example after a viral illness, during physical stress or while taking steroid medicines. A count that stays low can reflect an immune or bone marrow issue that a clinician can help sort out.
Common causes
- Recent viral or other infections
- Physical stress, surgery or severe illness
- Corticosteroid medicines
- Chemotherapy, radiation or other immune-suppressing treatments
- HIV infection
- Autoimmune conditions such as lupus
- Poor nutrition, including low zinc
- Less often, inherited immune conditions or an enlarged spleen
What can help
- Ask whether to recheck after you have recovered from any illness
- Review your medicines with your clinician, without changing them on your own
- Ask whether more testing, such as lymphocyte subsets, would be useful if it stays low
If it’s high
A high count (lymphocytosis) most often means your immune system is responding to something, such as a recent viral infection, and it is usually temporary. A count that stays high for weeks can have other causes, and a clinician may look at a blood smear or order more tests.
Common causes
- Recent viral infections, such as mononucleosis (EBV) or CMV
- Whooping cough (pertussis) and some other infections
- Physical or emotional stress, including hard exercise just before the draw
- Reactions to some medicines
- Having no spleen or an underactive spleen
- Less often, a lasting rise from a blood condition such as chronic lymphocytic leukemia
What can help
- Mention recent illness, vaccines, new medicines and hard exercise to your clinician
- Ask whether to repeat the test once you have fully recovered
- Ask what follow-up, such as a blood smear review, makes sense if it stays high
Usual ranges
What labs print as the reference range, by who was tested. Ranges differ a little between labs, so the range on your own report is the one your result is judged against.
The usual range depends on age. Choose an age to see the one that applies.
- 13+0.7–3.1 x10³/µL
Sources: Labcorp, Mayo Clinic Laboratories, ARUP Laboratories, Te Whatu Ora Health New Zealand, Waikato, Elsevier (via PubMed Central)
See Lymphocytes (abs) by age and sex, with the U.S. survey numbers where they exist.
How common is your level?
NHANES describes the US civilian, non-institutionalized population, not a 'healthy' reference group. People with disease, on medication, fasting or not (except fasting-subsample markers), smokers and so on are all included. A percentile says where a value sits among Americans of that sex and age, not whether it is normal.
Use the left and right arrow keys to read each age. Shift moves five years.
Reference data derived from CDC/NCHS National Health and Nutrition Examination Survey (NHANES), cycles 2015-2016, 2017-March 2020 (pre-pandemic), August 2021-August 2023. Analysis by bloodtesttracker.com; not endorsed by CDC, NCHS or HHS.
Explore Lymphocytes (abs) by age and sex: every percentile as a table, with a download.
What can affect your result
- Age: children have much higher counts than adults. Infants average roughly 5.5 to 7 x10³/µL, falling to about 2.0 to 2.4 in adulthood
- Posture: counts run higher standing than lying down
- Exercise and stress raise the count for a short time
- Recent infection or vaccination
- Steroid medicines lower the count
- Time between the draw and testing
- Lab method: atypical (reactive) lymphocytes are included unless the lab reports them separately
- Standing before the draw raises the lymphocyte count compared with lying down (about 23% higher in one small study of 19 volunteers).
- Hard exercise and acute stress can raise the count for a short time.
- Samples held longer than about a day before testing can give unreliable results; ARUP lists 24 hours at room temperature.
- Atypical (reactive) lymphocytes are counted as lymphocytes unless the lab reports them separately.
Any time of day. Try to avoid hard exercise just before the draw, and keep your posture similar when you compare results over time. Can change within days, for example during a viral illness, and usually settles within weeks after recovery.
When to talk to a clinician
See a clinician if your count stays above 4.0 x10³/µL (4,000 cells/µL) on repeat testing, especially with fevers, drenching night sweats, weight loss or swollen glands. For a low count, talk with a clinician if it is below 1.0 x10³/µL (1,000 cells/µL) on repeat testing, or if you get frequent or unusual infections.
Questions you could ask
- How does my lymphocyte count compare with my past results?
- Do my other white blood cell counts tell a consistent story?
- Could a recent infection, stress or hard exercise explain this result?
- Should we repeat the test in a few weeks, and would a blood smear review help?
- Could a recent illness or any of my medicines explain a low count?
- Should we recheck it, and is any other testing useful?
Questions people ask
Should I look at the absolute count or the percent?
The absolute count is usually more useful. The percent only tells you the share of your white cells, so it can look high when another cell type, such as neutrophils, is low even though your lymphocyte count is fine. Some labs, including Labcorp, give a range only for the absolute counts.
Why do labs list different normal ranges?
Labs test different groups of healthy people and use different analyzers. Adult lower limits run from 0.7 to 1.3 x10³/µL and upper limits from about 3.1 to 4.0 across the labs we checked. Compare your result with the range printed on your own report.
Can a cold or other recent illness change my count?
Yes. Viral infections often push lymphocytes up for a while, and counts can dip after some illnesses. Hard exercise, stress and steroid medicines can also change the count. If the result is outside the range right after an illness, a repeat test a few weeks later is common.
How do I convert between units?
x10³/µL, K/µL and x10⁹/L all mean the same thing, so 2.1 is 2.1 in each. Cells/µL is 1,000 times bigger, so 2,100 cells/µL is 2.1 x10³/µL.
Show the science and sources
Units
- 1 x10³/µL = 1 x10³/µL
- 1 x10³/µL = 1 x10⁹/L
- 1 x10³/µL = 1000 cells/µL
Open the Lymphocytes (abs) unit converter
Is a change real?
Lymphocytes (abs) naturally varies about 10.13% from test to test in the same healthy person. Between two results from the same lab, a change of roughly 31% or more is unlikely to be day-to-day noise or lab variation (95% reference change value). Source: Systematic review and meta-analysis of within-subject and between-subject biological variation estimates of 20 haematological parameters (Coskun A et al., EFLM WG-BV).
For clinicians and researchers
The absolute lymphocyte count (ALC) is the white cell count multiplied by the lymphocyte fraction. Analyzers classify lymphocytes by properties such as size, internal complexity and staining, and the count includes atypical or reactive lymphocytes unless the lab breaks them out. Textbook definitions (Mims): lymphocytosis is above 4,000/µL in adults and teenagers (above 8,000/µL in young children) and lymphocytopenia is below 1,000/µL; a French review (Berezne 2006) uses below 1,500/µL for adults. Adult reference intervals vary by lab: Labcorp 0.7-3.1 x10³/µL, Mayo Clinic Laboratories 0.95-3.07 x10⁹/L, ARUP 1.3-3.6 x10³/µL and Health NZ Waikato 1.0-4.0 x10⁹/L, so a result can be in range at one lab and flagged at another. Labcorp's published critical-value list (2024) has no entry for lymphocytes. Children have higher counts that fall through childhood. Absolute counts are preferred over percentages for interpretation (CAP checklist item HEM.23050). Subset counts (CD4, CD8, B and NK cells) are separate immune-category markers.
LOINC 731-0 (primary), 26474-7, 732-8. Specimen: whole-blood.
Sources
- Pediatric Testing Reference Ranges (CBC With Differential/Platelet, test 005009), Labcorp (2022)
- Labcorp sample patient report with CBC components (Sample Report 505271), Labcorp (2025)
- CBC - Overview: Complete Blood Cell Count (CBC) with Differential, Blood, Mayo Clinic Laboratories
- CBC with Platelet Count and Automated Differential (test 0040003), Hotline effective March 1, 2021, ARUP Laboratories (2021)
- CBC reference intervals (procedure HEM-2597.01, effective 14 November 2024), Te Whatu Ora Health New Zealand, Waikato (2024)
- Lymphocytosis, StatPearls (NCBI Bookshelf)
- Lymphocytosis, Lymphocytopenia, Hypergammaglobulinemia, and Hypogammaglobulinemia (Mims et al., in Hematology), Elsevier (via PubMed Central)
- Orientation diagnostique devant une lymphopénie (Diagnosis of lymphocytopenia; Berezne, Bono, Guillevin, Mouthon), La Presse Médicale (2006)
- Q&A: reporting percent and absolute differential reference ranges (CAP checklist item HEM.23050), CAP TODAY, College of American Pathologists (2014)
- Patient posture for blood collection by venipuncture: recall for standardization after 28 years, Revista Brasileira de Hematologia e Hemoterapia (2017)
- Blood Differential Test, MedlinePlus (National Library of Medicine)
AI-verified against cited sources. Awaiting expert review. Last reviewed 2026-10-03. How we build and check these pages.