This depends on the mode of the HIV transmission and the lifestyle of the HIV positive person. Majority of persons who are infected through blood transfusion develop symptoms on an average from 3 years to 5 years. With the other modes of transmission when the quantum of the virus is low, the person can remain healthy for 8 to 12 years or longer. If an HIV positive person improves his/her quality of life by adopting safer sex methods, has good nutrition, regular exercise, regular medical management, emotional support, does yoga and meditation, avoids stress and regularly treats other illnesses, continues to be active, and has an optimistic outlook, s/he is likely to live longer. Progressing from HIV + to AIDS is few weeks after the virus enters the body, some people have flu-like symptoms such as fever, body ache, and headache, (every infected person may not experience these). These symptoms disappear after a while, and then there is a long phase of 3 years to 12 years which is asymptomatic. Later when the immune system starts failing, AIDS sets in. The major and minor signs classified by World Health Organization for HIV are: Major Signs 1) Weight loss greater than 10% of body weight. 2) Fever for longer than one month, intermittent or continuous. 3) Chronic diarrhea for longer than one month, intermittent or constant. Minor Signs 1) Persistent cough for longer than one month. 2) General itchy dermatitis (skin irritation). 3) Recurrent herpes zoster (shingles). 4) Oropharyngeal candidasis (fungus infection in the mouth/throat). 5) Chronic progressive and disseminated herpes simplex infection. 6) Generalized lymphadenopathy (swelling of lymph glands). If a person has two major and two minor signs he is diagnosed as having AIDS. It is important to note that these symptoms are fairly common in various non-AIDS conditions also.