Understanding HIV: The Virus That Weakens the Immune System
Understanding HIV is one of the world's most important health issues, affecting the lives and health of millions of people.
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Contents
Understanding HIV is one of the world's most important health issues, affecting the lives and health of millions of people. While our knowledge of the disease is still insufficient, many people continue to hold misconceptions about how it is transmitted and how to prevent it. Having accurate information and understanding the nature of HIV is therefore extremely important for reducing infection rates and helping people living with the virus receive appropriate care. In this article, we will explore the basics of HIV — from infection, transmission, and prevention to treatment and support for people living with HIV. The goal is to provide accurate, clear knowledge that helps everyone understand and manage this issue more effectively.
HIV stands for Human Immunodeficiency Virus.
The human immunodeficiency virus is a lentivirus (“lenti” means “slow” in Latin; a type of virus that causes chronic and deadly diseases in humans and mammals that is characterized with long incubation periods) that attacks the cells of the immune system, which weakens the body’s defense against infections and diseases.
If it is overlooked and left untreated, HIV infection will reach its final stage, known as AIDS or acquired immunodeficiency syndrome. During this period, lethal infections and deadly diseases including cancer commonly arise.
How does HIV spread?
A sexually transmitted infection, human immunodeficiency virus is spread mainly by unprotected (i.e. condomless) sex including vaginal, anal, and oral sex. An infected partner may contaminate their partners when their blood, semen, or vaginal secretions enter their body.
Sharing needles and syringes when using drugs with people who are living with human immunodeficiency virus can also increase the risk of HIV spread.
HIV can also spread from blood transfusions, although the risk nowadays is very low because hospitals screen their blood supply. Mothers who are living with human immunodeficiency virus can also pass on the virus to their babies but when they receive treatment during pregnancy, the risk is also small.
What are the symptoms of HIV?
HIV catches white blood cells, which are called CD4 cells, and then gets inside these cells and multiplies itself. HIV later kills CD4 cells while its copies find other CD4 cells to repeat this process.
As a lentivirus, which is a type of retrovirus that is characterized with long incubation periods, HIV slowly destroys CD4 cells. This means that some people who are living with HIV may not have any symptoms for years as long their CD4 cells are in moderation and thus able to fight other infections and diseases normally.
There are some people who experience flu-like symptoms such as fever, sore throat, swollen glands, or a skin rash. While these symptoms will go away without treatment, the virus remains in their blood.
People who are living with human immunodeficiency virus and already have a weakened immune system are more likely to experience symptoms such as:
- Fever
- Fatigue
- Sore throat
- Headache
- Rash outbreak that is measles-like in appearance
- Muscles aches and joint pain
- Mouth sores
- Genital rashes and sores
- Rectal rashes and sores
- Body aches, loss of appetite, or unintentional weight loss.
- Diarrhea
- Nausea
- Vomiting
- Stiff neck; swollen lymph glands, mainly on the neck
- Coughing
- Night sweats
In addition, another common symptom in people with living HIV is pruritic papular eruption (PPE), but this is usually found in the final stages of HIV infection or AIDS.
How do I know I have human immunodeficiency virus?
You can have human immunodeficiency virus and not know of it. According to research, 1 in 7 people who are HIV-positive are not aware of it. Sadly, in many cases, people who are unaware and refuse to get tested only find out about the infection when HIV already has reached the final stages. The only way to know if you are infected is to get an HIV test.
You can get tested at most general hospitals and some of them also provide treatment for HIV. In Thailand, there are several clinics that specialize in sexually transmitted infections that can also be an option
Getting an HIV test is an important step in knowing your own HIV status. It allows people who are infected to receive care and treatment in time and helps prevent the virus from being passed on to others. There are several HIV testing methods, which differ in both speed and accuracy. The most common ones include blood tests that look for antibodies and tests that detect the virus's genetic material. There are also rapid tests that take only a few minutes and are well suited for initial screening. These tests can be done at healthcare facilities, public health service centers, or even with a self-testing kit. Getting an HIV test is an important first step in caring for your sexual health and building the confidence to live a good-quality life.
Verified references
Links and relevance to the article’s main topic were reviewed on 13 August 2026. Each source supports only the scope stated in the original document and does not replace personalised medical, legal, or service advice.
- WHO: HIV and AIDS fact sheet Accessed 13 August 2026
