Find Information About:

Drugs & Supplements

Get information and reviews on prescription drugs, over-the-counter medications, vitamins, and supplements. Search by name or medical condition.

Pill Identifier

Pill Identifier

Having trouble identifying your pills?

Enter the shape, color, or imprint of your prescription or OTC drug. Our pill identification tool will display pictures that you can compare to your pill.

Get Started
My Medicine

My Medicine

Save your medicine, check interactions, sign up for FDA alerts, create family profiles and more.

Get Started

WebMD Health Experts and Community

Talk to health experts and other people like you in WebMD's Communities. It's a safe forum where you can create or participate in support groups and discussions about health topics that interest you.

  • Second Opinion

    Second Opinion

    Read expert perspectives on popular health topics.

  • Community


    Connect with people like you, and get expert guidance on living a healthy life.

Got a health question? Get answers provided by leading organizations, doctors, and experts.

Get Answers

Sign up to receive WebMD's award-winning content delivered to your inbox.

Sign Up

HIV & AIDS Health Center

Font Size

HIV, AIDS, and the CD4 Count

What the CD4 Count Test Results Mean continued...

The test does not always correspond with how well you are feeling. For example, some people can have high CD4 counts and do poorly. Others can have low CD4 counts and have few complications.

If your CD4 count goes down over several months, your doctor may recommend:

  • Beginning or changing antiretroviral therapy.
  • Starting preventive treatment for opportunistic infections.

Public health guidelines recommend starting on preventive antiretroviral therapy for all HIV positive patients whether or not there are symptoms. If therapy is effective, your CD4 count should go up or become stable.

Most doctors recommend starting medication for opportunistic infections at these levels:

  • Less than 200: pneumocystis pneumonia (PCP).
  • Less than 50: mycobacterium avium complex (MAC).

Factors That Can Affect Your CD4 Count

You should know that other factors can influence how high or low your CD4 count is.

  • CD4 counts tend to be lower in the morning and higher in the evening.
  • Acute illnesses such as pneumonia, influenza, or herpes simplex virus infection can cause CD4 counts to go down for a while.
  • If you have a vaccination or when your body starts to fight an infection, your CD4 counts can go up or down.
  • Cancer chemotherapy can cause CD4 counts to go way down.
  • Fatigue and stress can also affect test results.

For these reasons:

  • Try to use the same lab each time.
  • Have your tests done at the same time of day each time.
  • Wait for at least a couple of weeks after an infection or vaccination before getting a CD count test.

WebMD Medical Reference

Reviewed by David T. Derrer, MD on August 17, 2014
1 | 2

Today on WebMD

How much do you know?
contemplative man
What to do now.
Should you be tested?
HIV under microscope
What does it mean?
HIV AIDS Screening
man opening condom wrapper
HIV AIDS Treatment
Discrimination Stigma
Treatment Side Effects
grilled chicken and vegetables
obese man standing on scale
cold sore