During the initial stages of the window period, the infected person starts developing frequent flu-like illnesses and infections. As the ability of the body to fight diseases diminishes, the infected person becomes susceptible to prolonged infections. These aliments are cured over a period of time as the body’s immune system is still active. However, at this stage, the amount of viruses in the blood stream is quite high. The most common symptoms that one can experience during this stage include fever, muscle soreness, rashes, headaches, joint pain, sweating at night and diarrhea to name a few.

During the initial stage, the body is still capable of fighting bacteria, viruses and other mild infections. However, after a period of time, HIV viruses, which are multiplying actively within the body, completely destroy the CD4+ and T4 cells which are the primary infection fighters. Once these cells are destroyed, the immune system of the body weakens and the infected person starts developing chronic symptoms including fever, severe weight loss, short term memory loss and swollen lymph nodes. During this period, the consumption of nutrition rich food becomes imperative.

The progressive symptoms become evident when the HIV infection eventually progresses to AIDS owing to the lack of proper treatment. The window period of such progression has been estimated to be around 10 years on an average. At this stage, the immunity system of the body is severely damaged and the infected person becomes prone to even those infections that otherwise would never trouble a person with an intact immune system. At this stage, one has to remain extra cautious to keep away from catching infections. The progressive infection symptoms include soaking night sweats, chronic diarrhea, lesions and white spots in mouth, persistent and unexplained fatigue, and distorted and blurred vision to name a few.

Pneumonia is the most common disease among HIV infected people. This disease is very rare among healthy individuals; but for HIV infected ones, it is a predominant cause of death. An individual who has less than 200 per µL blood CD4+ cell count is more susceptible to it. Apart from this, tuberculosis infection also indicates the onset of advanced HIV infection. Symptoms of progression of HIV to AIDS are not localized but generally constitutional. During this stage, a majority of aliments affect bone marrow, urinary as well as gastrointestinal tracts, liver and central nervous system.

At its nascent stages, the two most common symptoms are excessive weight loss and wasting syndrome. These can be lethal if not treated as these are the cause of death in 25 percent HIV infected individuals. HIV infection causes changes in the entire metabolism. Moreover, as the body is busy fighting infections, the lean mass is utilized for energy, causing weight loss. The intestines absorb fewer nutrients while wasting most of them, thus, magnifying the condition. Triple drug therapy is used worldwide to treat this syndrome.

During the advanced stages of HIV infection, infected individuals suffer from gastrointestinal diseases due to fungal as well as viral infections. Patients may also develop chronic diarrhea and other parasitic infections. Diarrhea onsets at the later stages of HIV infection signifies a change in the manner how intestinal tract poorly absorbs nutrients. In some rare cases, diarrhea can be a side effect of consuming HIV treatment drug.

At the later stages, viral organisms attack the weakened peripheral nervous system that carries information to the brain, causing nerve damage. The nerves do not work properly and the body suffers from pain and numbness. There is tingling and burning sensations in legs and arms while it becomes quite impossible to control the muscles at one’s will. The patient suffers from frequent muscle cramps. It can be fatal when the muscles of essential organs like heart, bladder and liver are affected.

When the central nervous system is affected by HIV infection then the infected individual develops neurological as well as psychiatric aliments. Among such aliments, the most common ones include Toxoplasmosis, Progressive multifocal leukoencephalopathy (PML), and AIDS dementia complex. Toxoplasmosis affects the brain, eyes and lungs causing chronic fever, headaches, nausea and sometimes seizures. PML impairs the transmission of nerve impulses and signifies severe weakening of the immune system. ADC is when brain is severely infected by HIV virus and there are several neurological impairments. It can cause lethal bipolar disorder in the patient.

As AIDS reaches its last stages, it completely takes away the ability to fight cancer and other infections. Most HIV patients suffer from skin tumors and co-infections caused by oncogenic DNA virus. Kaposi’s sarcoma, the most common tumor, causes appearance of purplish nodules on the skin. This tumor generally affects mouth, gastrointestinal tract and lungs. Among women, breast cancer as well invasive cervical cancer are prevalent. With the use of antiretroviral drugs, the growth of such aliments can be slowed down in HIV infected individuals.