When you live with HIV, blood tests (your “labs”) help you and your care team see how your body is doing. Two tests matter most: viral load and CD4 count. You may also see other labs that check your kidneys, liver, cholesterol, sugar, and more. (hiv.gov)
Viral load: how much HIV is in your blood
- What it is: A test that measures the amount of HIV in a small sample of blood.
- What you want to see: A lower number. On treatment, the goal is undetectable—so little virus that the lab can’t measure it.
- Why it matters: Staying on HIV meds as prescribed can get you to undetectable and keep you there. People who get and keep an undetectable viral load will not transmit HIV to their HIV-negative partners through sex (often called U=U).
If your viral load goes up: Don’t panic—tell your provider. It could be missed doses, a drug interaction, or (less often) resistance to a medicine. Your team can help you get back on track, and may order drug-resistance testing to choose medicines that work best for you.
CD4 count: how strong your immune system is
- What it is: A count of the infection-fighting CD4 cells in your blood.
- What you want to see: A higher number over time.
- Why it matters: A low CD4 count means your body has a harder time fighting infections. A CD4 under 200 means HIV has reached stage 3 (AIDS), and your provider will act to protect you from serious infections.
Other common labs you might see
Your provider may order some of these, especially when starting or changing meds:
- Kidney and liver tests: Make sure your organs are healthy and handling your medicines well.
- Cholesterol and blood sugar: Some HIV meds can affect these; your team watches them to protect your heart and overall health.
- Hepatitis A, B, and C tests: Check for current or past infection and whether vaccines or treatment are needed.
- Complete blood count (CBC): Looks for anemia or infection.
- Sexually transmitted infection (STI) screening: Tests for syphilis, gonorrhea, and chlamydia so you can get treated quickly.
- Drug-resistance test (genotype): Helps pick the most effective HIV meds for you.
How often are labs checked?
It depends. After you start HIV treatment, not every test is done at every visit. Your provider will decide the timing based on how you’re doing and which meds you take.
HIV.gov
Quick cheat sheet
- Viral load: Lower is better. Undetectable is the goal → great for your health and means no sexual transmission (U=U).
- CD4 count: Higher is better. Under 200 needs extra care and protection from infections.
- Other labs: Check organ health, cholesterol/sugar, hepatitis, STIs, and which meds will work best.
Talk with The Project care team
- Have questions about your most recent labs? Bring your results to your next visit or send us a message in MyChart.
- New to care or ready to re-engage? We can help you get labs done and start (or restart) treatment.
- Need an HIV test or want to talk about PrEP? We offer confidential testing and same-day PrEP starts for many patients.
This post is for general education and doesn’t replace medical advice. Your provider is the best person to explain your individual results.
