AIDS is caused by human immunodeficiency virus (HIV). HIV kills or damages the body's immune system cells.
There are two types of HIV. Type I and Type II. Type I is more common in India.

AIDS is generally caused by unprotected sex with an infected partner. It may also spread through the use of infected syringes of HIV infected people and blood transfusions.

The first signs of AIDS is influenza (flu) like symptoms or may be swollen glands but at times symptoms might not appear. Symptoms may appear after two or three months. Generally, blood test is done to confirm the diagnosis. There is no cure, but there are many medicines to fight/ control HIV infection.


There are 3 main stages of AIDS:
Acute symptoms, clinical latency and severe symptoms

Acute symptoms: The majority of people infected by HIV develop a Influenza (flu) like illness within a month or two after the virus enters the body. This illness, known as primary or acute HIV infection, may last for a few weeks. Possible symptoms include:

  • Headache
  • Fever
  • Sore throat
  • Muscle soreness
  • Rash
  • Mouth or genital ulcers
  • Swollen lymph glands, mainly on the neck
  • Joint pain
  • Diarrhea
  • Night sweats

Clinical Latency:
There is persistent swelling of lymph nodes during clinical latent HIV. Else, there are no specific signs and symptoms. However, body remains infected with the virus.

Severe Symptoms:

  • Headaches
  • Blurred and distorted vision
  • Cough and shortness of breath
  • Persistent white spots or unusual lesions on your tongue or in your mouth
  • Soaking night sweats
  • Shaking chills or fever higher than 100 F (38 C) for several weeks
  • Chronic diarrhea
  • Persistent, unexplained fatigue
  • Weight loss
  • Skin rashes


A person becomes infected with HIV/AIDS by several ways:

  • Blood transfusions: In some cases, the virus may be transmitted through blood transfusions.
  • Sharing infected needles: HIV can be transmitted through needles and syringes contaminated with infected blood.
  • Physical Contact: The most frequent mode of transmission of HIV is through sexual contact with an infected person. 
  • From mother to child: A pregnant woman infected with HIV virus can transmit the virus to her fetus through their shared blood circulation, or an infected nursing mother can transmit it to her baby through her breast milk.


HIV test is done to detect human immunodeficiency virus in saliva, serum or urine. The UNAIDS/WHO policy statement on HIV Testing states that conditions under which people undergo HIV testing must be anchored in a human rights approach that pays due respect to ethical principles . According to these principles, the conduct of HIV testing of individuals must be: 

Confidentiality: In developing countries, home-based HIV testing and counseling (HBHTC) is an emerging approach for addressing confidentiality issues. HBHTC allows individuals, couples, and families to learn their HIV status in the convenience and privacy of their home environment. Rapid HIV tests are most often used, so results are available for the client between 15 and 30 minutes.

  •  Accompanied by counseling (for those who test positive).
  •  Conducted with the informed consent of the person being tested. Diagnosis of HIV/AIDS, several types of tests can help physician to determine what stage of the disease. These tests include:

Window period: Antibody tests may give false negative (no antibodies are detected despite the presence of HIV) results during the window period, an interval of three weeks to six months between the time of HIV infection and the production of measurable antibodies to HIV sero conversion.

CD4 count: CD4 cells are a type of white blood cell that's specifically targeted and destroyed by HIV. A healthy person's CD4 count can vary from 500 to more than 1,000. Even if a person has no symptoms, HIV infection progresses to AIDS when his or her CD4 count becomes less than 200.

Rapid or point-of-care testsThe rapid test is an immunoassay used for screening, and it produces quick results, in 20 minutes or less. Rapid tests use blood or oral fluid to look for antibodies to HIV. If an immunoassay (lab test or rapid test) is conducted during the window period  (i.e., the period after exposure but before the test can find antibodies), the test may not find antibodies and may give a false negative result. All immunoassays that are positive need a follow up test to confirm the result.

ELISA (enzyme-linked immunosorbent assay)ELISA is set of blood tests used to diagnose HIV infection.  ELISA test is performed by inserting a needle to draw blood. A positive result on the ELISA screening test does not necessarily mean that the person has HIV infection. Certain conditions may lead to a false positive result, such as Lyme disease, syphilis, and lupus. A positive ELISA test is always followed by a Western blot test. A positive Western blot confirms an HIV infection. Negative tests do not rule out HIV infection. There is a period of time (called the "window period") between HIV infection and the appearance of anti-HIV antibodies that can be measured.

RNA tests detect the virus directly (instead of the antibodies to HIV) and thus can detect HIV at about 10 days after infection as soon as it appears in the bloodstream, before antibodies develop. These tests cost more than antibody tests and are generally not used as a screening test, although your doctor may order one as a follow-up test, after a positive antibody test, or as part of a clinical workup.

Western Blot: A positive ELISA test is always followed by a Western blot test which confirm the HIV infection.

*NHP provides indicative information for better understanding of health. For any treatment and diagnosis purpose you should consult your physician.


Definitive cure for AIDS is yet to be disocvered. However, some medicines, given at certain stages of the disease, depending upon the CD4 count in the blood of the patient, can prolong the life of HIV positive persons.

  • Reverse transcriptase (RT) inhibitors - It interferes with a critical step during the HIV life cycle and keep the virus from making copies of itself.
  • Protease inhibitors - It interferes with a protein that HIV uses to make infectious viral particles.
  • Fusion inhibitors - It blocks the virus from entering the body's cells.
  • Integrase inhibitors - It blocks an enzyme HIV needs to make copies of itself.
  • Multidrug combinations - It combines two or more different types of drugs into one. These medicines help people with HIV, but they are not perfect. They do not cure HIV/AIDS. People with HIV infection still have the virus in their bodies. They can still spread HIV to others through unprotected sex and needle sharing, even when they are taking their medicines.

*NHP provides indicative information for better understanding of health. For any treatment and diagnosis purpose you should consult your physician.


HIV prevention refers to practices done to prevent the spread of HIV/AIDS. HIV prevention practices may be done by individuals to protect their own health:

  1. Promoting sex-education among teen-agers
  2. Protected physical contact through the use of condoms reduces the risk of HIV/AIDS
  3. Providing awareness among the population about their HIV status especially in high risks population, High risks population involves sex workers and their partners, Intravenous drug users, truck drivers, labor migrants, refugees and prisoners.
  4. Safe injections: Using unused syringes will help to prevent HIV infections.
  5. Male circumcision: It is the surgical removal of the foreskin (prepuce) from the human penis.
  6. Safe blood transfusion procured only from authorized and accredited blood banks.
  7. Counseling of HIV positive pregnant mother on the issue of how to prevent parent to child transmission (PPTCT).


  • PUBLISHED DATE : Jun 06, 2015
  • LAST UPDATED ON : Jun 06, 2015
The content on this page has been supervised by the Nodal Officer, Project Director and Assistant Director (Medical) of Centre for Health Informatics. Relevant references are cited on each page.