Depending on how severe the infection at exposure is, patients usually develop symptoms at around 7 years after the entry of the virus.

Symptoms can be in the form of any single or multiple system involvement. Infection occurs which either does not respond to routine treatment because of resistant strains or, if it responds, it does so after a long time only to recur. Such repeated infections debilitate the body leading to death. The drugs too, often produce rare reactions in AIDS patients not commonly seen otherwise. Some of the commonly encountered symptoms in HIV positive patients would be as follows.
 
 

RESPIRATORY	GASTROINTESTINAL	NERVOUS	SKIN
Cough	Persistent diarrhoea (by common and rare pathogens)	Headache	Xerosis (Dry Skin)
Breathlessness	Difficulty in swallowing or eating	Altered Personality	Purpuric Spots
Rapid Breathing	Perianal discomfort	Lethargy	Hair loss/ Greying of hair
Blood stained cough		Dementia
Effusions in Lung cavity		Convulsions	Bacterial Viral infections Fungal
		Meningitis
		Visual Impairment

[It is the causative organisms of these common symptoms, which are important in HIV positive].

There are a few conditions, which were extremely rare till now, the occurrence of which almost confirms AIDS and are called markers.
A few of these could be
a)     Recurrent/ widespread Herpes Zoster
b)     Oesophageal Candidiasis
c)      Kaposis Sarcoma in a young person
d)     Oral Hairy Leucoplakia