This section of the website is for UK healthcare professionals only. If you are not a healthcare professional, please click here.
This section of the website is for UK healthcare professionals only. If you are not a healthcare professional, please click here.

This section of the website is for members of the public. If you are a healthcare professional,visit the HCP section of the site. This website is not intended to replace the advice of a healthcare professional. You should consult your doctor or another suitably trained healthcare provider when considering what type of treatment is most appropriate for you.


What is HIV?

HIV, or human immunodeficiency virus, is a virus that can cause acquired immune deficiency syndrome (AIDS). HIV is different from most other viruses because it attacks the body’s immune system.

The immune system fights infections that harm the body. The HIV virus find and attacks CD4 cells that the immune system needs to fight disease. Regular blood tests can measure the amount of virus present in the body and the overall health of HIV patients.

CD4 Count - amount of CD4 cells (immune system cells) in the blood

  • HIV lowers the CD4 cell count, which makes it more likely for HIV patients to get sick
  • Generally speaking, a higher CD4 count is better, but the CD4 count can vary from person to person.

HIV Viral load - Amount of HIV in the blood

  • When taking HIV treatments, the viral load can go down to very low levels in the blood (less than 40 copies/ml), also known as an "undetectable viral load".
  • An undetectable viral load is the goal of HIV treatment

Lipids - Amount of triglycerides, "bad cholesterol" (LDL), and "good cholesterol" (HDL) in the blood

  • HIV and some HIV treatments may increase the "bad cholesterol" (LDL) and decrease the "good cholesterol" (HDL)
  • LDL over 3 mmol/L, triglycerides over 1.5 mmol/L = more risk of heart disease
  • HDL under 1 mmol/L in men and under 1.2 mmol/L for women = more risk of heart disease

Alternatively, see the links below for more information about charities and patient support groups for those affected by HIV.

Contact Information

Our address for correspondence is:

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Hertfordshire,
EN11 9BU

Alternatively you can telephone: 01992 467272

Or Email: medicalinformationuk@merck.com