What Is HIV? Understanding Causes, Symptoms, Treatments and More
Medically Reviewed by Dr. Samantha Miller, MBChB
Human immunodeficiency virus, more commonly known as HIV, is a virus which, without treatment, leads to deterioration of your body’s immune system to a point where your body has trouble fighting off mild infections. When your immune system has become severely damaged after a prolonged period with HIV, it’s known as acquired immune deficiency syndrome, or AIDS.
HIV is a blood-borne retrovirus that infects specific cells in the human immune system called CD4 T cells. CD4 cells normally play an important role in your immune system. There, they’re responsible for detecting harmful pathogens like bacteria and viruses so your body can begin fighting off those pathogens.
There’s no cure for HIV, and once you contract it, the virus will remain in your body for life. Over time, if left untreated, HIV can progressively damage your immune system to a point where you become susceptible to AIDS-defining illnesses — infections and conditions that wouldn’t normally make you sick if your immune system was functioning typically.
Symptoms, Causes and Risk Factors of HIV
Many people have no symptoms at all after initially becoming infected with HIV. However, most people do experience some non-specific symptoms within the first few weeks after infection. This means the symptoms are typical of many illnesses and don’t immediately point to one specific condition as their cause. For HIV, non-specific symptoms include:
- Flu-like symptoms
- Stiff or aching muscles
- Mouth ulcers
- Sore throat
- Sweating at night
- Swollen lymph glands
After this initial illness, which is known as “seroconversion,” most people live for many years without any symptoms until the virus has harmed their immune system to a point where they start to become significantly more vulnerable to infections and illnesses.
HIV is present in the blood, pre-ejeculatory fluid, semen, vaginal fluid, rectal fluid and breast milk of people with the virus. HIV can be transmitted by:
- Sexual contact, including vaginal, anal and oral sex, and through the sharing of sex toys
- Sharing of needles, which most commonly occurs in groups of people who are using intravenous drugs
- Receiving a blood transfusion from an infected individual; this is rare in developed countries, as donor blood is usually screened for blood-borne viruses such as HIV
- Childbirth; HIV can be passed from the pregnant parent to the child during pregnancy or childbirth
- Breastfeeding; HIV exists in breast milk and can be passed on to a child
In rare cases, HIV can also be spread by:
- Ingesting pre-chewed food from someone who has the virus; this is a common practice in some underdeveloped countries and is generally done to feed small children or elderly people
- Being bitten by someone or biting someone who has HIV
- Kissing, if there is bleeding within the mouth
- Undergoing body-modification procedures such as tattoos or piercings if tools are not properly sterilized between clients
The vast majority of cases of HIV in the United States are acquired via sexual contact. HIV cannot be spread by:
- Insect bites
- Casual contact such as shaking hands or hugging
HIV is usually diagnosed via a blood test. The most accurate and reliable test is known as a fourth-generation test. It checks for both a specific part of the HIV viral structure (called the p24 antigen) and your own body’s response to the infection (HIV antibodies).
Point-of-care tests are also available, and they differ from fourth-generation tests. These take a small sample of saliva or blood and provide a result in less than an hour. However, these are less sensitive and may not pick up all cases of HIV due to the smaller concentration of antibodies in the saliva or small blood sample. You should always follow up a point-of-care result with a confirmatory laboratory test. There are also self-sampling and home-testing kits available.
Any positive result is usually repeated to check it wasn’t a rare false-positive. If you’re diagnosed with HIV, you’ll be referred to a specialist HIV center to discuss treatment right away.
HIV has a window period, meaning it can take a certain length of time for a test to be able to detect the virus in your body. Many newer tests can determine results in 99% of people 45 days following their potential exposure. If you think you might have been exposed to HIV, it may not show up in a blood test for 45 days. Point-of-care testing and at-home testing can have an even longer window period, sometimes lasting up to 12 weeks.
Treatment for HIV
There is no cure for HIV, but the infection can be managed, allowing people with the virus to lead long and normal lives. Treatment for HIV usually involves a number of different antiretroviral (ARV) drugs. The virus requires an enzyme called protease in order to replicate, so treatment will involve protease inhibitors as well as ARV drugs. This combination of medications is called highly active antiretroviral treatment, or HAART.
The aim of treatment is to reduce the level of circulating virus particles in your body to a point where HIV is no longer detectable. This means that the virus is at such low levels that it won’t cause nearly as much damage to your immune system, and you likely won’t be able to transmit it to anyone. Undetectable means untransmissable. Many people reach this level within six months of treatment.
HIV drugs, like any medication, can cause side effects, such as nausea, diarrhea, headache and rash. Some people experience long-term side effects, such as changes in blood cholesterol levels or interference with liver or kidney functioning. You’ll be regularly monitored for these side effects once you start medication therapy.
How well the treatment is working is monitored by two parameters: the HIV viral load, meaning how many viral particles are present in your blood, and the CD4 count, which is a measure of how much the HIV virus has damaged specific blood cells of your immune system.
Post-exposure prophylaxis, or PEP, is a set of medications that you can take very soon after potential exposure to HIV. In most cases, these drugs can prevent infection from occurring. This treatment should only be used in an emergency and must be taken within 72 hours of exposure. PEP is usually taken for a period of 28 days.
Pre-exposure prophylaxis, or PrEP (available under the brand names Truvada® and Descovy®), is a medication that you can take if you’re at high risk of contracting HIV. These drugs can protect you from acquiring an infection with the virus. You can take PrEP daily or “on demand,” in which you take the medication right before you could potentially be exposed to the virus.
HIV is a chronic condition that currently has no cure, but people with the virus have plenty of effective options for managing the condition and living comfortably. Without treatment, nearly every HIV patient will go on to develop AIDS. However, when doctors detect HIV early and begin providing prompt treatment, the prognosis for people with HIV is very good. Nowadays, someone who’s diagnosed early with a high CD4 count has the same life expectancy as someone without HIV. However, people with HIV do appear to develop some other conditions at earlier ages than those without HIV — including cardiovascular disease, kidney disease, lung disease, diabetes and cancer — which may equate to differences in quality of life.
If someone doesn’t get treatment early, the virus will progress and weaken their immune system, which may cause more complications later in life. However, treatment can still be effective, no matter when the virus is diagnosed.
There’s a very small group of people who, despite having HIV in their bodies, never develop AIDS. These patients are called “long-term nonprogressors,” and it’s not clear what makes them resistant to the effects of HIV.
The best way to prevent the spread of HIV is to practice safe sex, as this is how most cases are transmitted. Consistent and correct condom use can prevent the spread of the virus. Sharing needles when misusing injectable drugs is another common form of transmission, and it’s important to never share another person’s needles or injecting equipment. If you’re looking for help in overcoming a drug addiction, contact the Substance Abuse and Mental Health Services Administration National Helpline at 1-800-662-4357 for free and confidential counseling.
HIV can be transmitted from a pregnant parent to their unborn child, so it’s important if you have HIV and become pregnant to inform your obstetrician immediately. They can help you take steps to reduce the risk of spreading the disease to your unborn baby. Consider the use of PrEP to prevent infection acquisition if you’re unable to avoid potential contact with HIV.