Interpret Your CD4+ T Cell Count Results
Enter your CD4 value below and get an instant, free AI interpretation — a plain-English explanation checked against WHO/IFCC reference ranges.
Medical Disclaimer
This AI-generated interpretation is for educational purposes only and does not constitute medical advice, diagnosis, or treatment. Results may vary based on individual health factors not captured here.
Always consult a qualified healthcare professional before making any health decisions. Read full disclaimer →
CD4+ T Cell Count Normal Ranges
CD4+ T cells (helper T cells) are the primary target of HIV.
| Age Group | Reference Range | Unit | Notes |
|---|---|---|---|
| Adults (18–64) | 500 – 1500 | cells/µL | Normal immune function |
| All ages | 200 – 499 | cells/µL | Moderate immunosuppression |
Also reported in: cells/mm³.
Critical (Panic) Values
Critical Low: < 200 cells/µL. Values outside these limits require immediate clinical attention.
Why Doctors Order the CD4+ T Cell Count Test
CD4 count is the primary marker of immune status in HIV. A count below 200 cells/µL defines AIDS and is the threshold for starting prophylaxis against Pneumocystis jiroveci pneumonia (PCP), the most common AIDS-defining opportunistic infection.
How to Enter Your CD4 Result
CD4+ T Cell Count can be reported in cells/µL or cells/mm³. Choose the unit printed next to your result on the lab report so it is compared with the matching reference range.
What a Low or High CD4 Can Be Associated With
Below the reference range
- HIV infection (progressive CD4 depletion)
- AIDS (CD4 <200 cells/µL)
- Corticosteroid therapy (reduces CD4 counts transiently)
- Acute illness or surgery (transient decrease)
- Diurnal variation (CD4 is lower in the morning)
Above the reference range
- Effective antiretroviral therapy (ART) restoring immune function
- In HIV-negative individuals: normal immunological variation, infections (reactive lymphocytosis)
This interpreter flags a result at or below 200 cells/µL as a critical value. Results that extreme are uncommon — contact your doctor promptly, and seek urgent medical care if you feel unwell.
These are common associations, not a diagnosis. A single result is read alongside your symptoms, history and other tests — discuss it with your doctor.
What Can Change Your CD4 Result
Before you read too much into a result, consider whether any of these applied:
- Diurnal variation (counts are ~25% higher in afternoon vs. morning)
- Acute illness, infections, and vaccinations temporarily reduce CD4 count
- Corticosteroids reduce CD4 counts
- Sample processing delays (>24 hours may affect accuracy)
Preparing for the test: CD4 count has significant biological variation: time of day (higher in evening), intercurrent illness, and technical factors affect results. Ideally measure consistently at the same time of day.
Symptoms That Often Prompt CD4 Testing
- CD4 200–500: increased risk of TB, bacterial pneumonia, herpes zoster
- CD4 <200: PCP pneumonia (breathlessness, dry cough, fever), oral thrush
- CD4 <100: toxoplasmosis (brain lesion — headache, confusion, seizures), cryptococcal meningitis
- CD4 <50: CMV retinitis (vision loss), disseminated MAC (fever, weight loss, night sweats)
- Constitutional: fatigue, weight loss, night sweats
Want the full clinical guide to CD4+ T Cell Count?
Reference ranges, causes, symptoms, preparation, and FAQs.