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When to start treatment

In the UK, standards for HIV treatment and care are set and monitored by the British HIV Association, or BHIVA, the professional association for HIV doctors and other healthcare professionals. These standards are reviewed regularly. The most recent guidelines on HIV treatment were produced in 2012.

There is no clear point when anyone with HIV should start treatment with anti-HIV drugs. Your doctor will discuss a range of issues with you, before working with you to decide when you should start. This will include weighing up the likely benefits and risks for you of starting treatment as opposed to waiting until later.

It is recommended in the UK HIV treatment guidelines that you start taking HIV treatment immediately if you are ill because of HIV, or if you have an AIDS-defining illness.

If you do not have any symptoms, then these guidelines recommend that you start treatment when your CD4 cell count is around 350. CD4 cells are a type of immune system cell, and doctors use the number of CD4 cells you have as a marker of the health of your immune system. Clinics use a test that measures the number of CD4 cells in a cubic millimetre of blood. CD4 cell counts in HIV-negative people range from about 500 to 1500. You can find out more about CD4 cell counts in the NAM booklet CD4, viral load & other tests.

Your doctor should start discussing HIV treatment with you when your CD4 cell count is approaching 350. Once your CD4 cell count is around 350, you are advised to start treatment as soon as you are ready. In some situations – for example, if you have another health condition such as hepatitis – your doctor may recommend you start treatment when your CD4 cell count is still above 350. Studies to determine the best time to start HIV treatment are being carried out.

Your doctor may ask you if you want to participate in a clinical trial. Clinical trials for people starting HIV treatment may look at the best time to start HIV treatment, or compare different combinations of anti-HIV drugs. You can find out more about taking part in a clinical trial in NAM’s factsheets at

Starting HIV treatment with a low CD4 count

Modern HIV treatment is highly effective. Many people who start HIV treatment when their CD4 count is already low (200 or under) will see it start to climb after starting treatment. Long-term HIV therapy can result in your CD4 count returning to the normal level for someone of your age. However, if possible, it is better to start treatment before your CD4 count drops this low. It can be harder to bring your CD4 count back up to a normal level for your age if it has been very low at one time.

Anti-HIV drugs

Published March 2012

Last reviewed March 2012

Next review December 2014

Contact NAM to find out more about the scientific research and information used to produce this booklet.

This content was checked for accuracy at the time it was written. It may have been superseded by more recent developments. NAM recommends checking whether this is the most current information when making decisions that may affect your health.