CD4 and viral load: two essential blood tests
Your CD4 and viral load results are the main tests used to monitor your health.
CD4 tests
CD4 tests measure your immune system. Results are given as cells/mm3. Above 500 is considered ‘normal’.
- Your CD4 count is important for deciding when to start treatment.
- Even if you start with a very low CD4 count, once you start treatment, your immune system can become strong enough for your body to be able to recover from HIV-related illnesses.
- UK guidelines recommend starting treatment when your CD4 count is around 350, but some people can start earlier.
Viral load tests
Viral load tests tell you how much virus is in a small sample of blood. Results are given as copies/mL.
- Viral load tests tell you how much virus is in a small sample of blood. Results are given as copies/mL.
- If you are on treatment, viral load tests show how well your treatment is working. You need to aim to get this ‘undetectable’. This means less than 50 copies/mL.
- Getting undetectable and staying there shows that the drugs are still working.
- If the viral load doesn’t become undetectable or it increases later, it means the drugs may not be working or that you may not be taking them correctly.
- Any unusual result should be checked with a second test before making a change in treatment.
- A high viral load (over 100,000 copies/mL) can be a reason to start treatment at any CD4 count.