HIV infection progresses in stages. These stages are based on your symptoms and the amount of the virus in your blood. Most people go through the following stages after being infected with HIV:

Initial stage (acute retroviral syndrome)

Acute retroviral syndrome is an illness with symptoms like mononucleosis. It often develops within a few days of infection, but it may occur several weeks after the person is infected. Symptoms may include:

• Abdominal cramps, nausea, or vomiting.
• Diarrhea.
• Enlarged lymph nodes in the neck, armpits, and groin.
• Fever.
• Headache.
• Muscle aches and joint pain.
• Skin rash.
• Sore throat.
• Weight loss.

These first symptoms can range from mild to severe and usually disappear on their own after 2 to 3 weeks.

Chronic stage

It may take years for HIV symptoms to develop. But even though no symptoms are present, the virus is multiplying (or making copies of itself) in the body during this time. HIV multiplies so quickly that the immune system cannot destroy the virus. After years of fighting HIV, the immune system starts to weaken.

A doctor may suspect HIV if symptoms persist or if a cause of the symptoms (such as the flu) cannot be identified. HIV may also be suspected when several of the following symptoms are present:

• Diarrhea or other bowel changes
• Fatigue
• Fever
• Loss of appetite or unexplained weight loss
• Dry cough or shortness of breath
• Nail changes
• Night sweats
• Swollen lymph nodes in the neck, armpits, and groin
• Pain when swallowing
• Confusion, difficulty concentrating, or personality changes
• Repeated outbreaks of cold sores or genital herpes sores
• Tingling, numbness, and weakness in the limbs
• Mouth sores or a yeast infection of the mouth (thrush)

Also, HIV may be suspected when a woman has at least one of the following:

• More than 3 vaginal yeast infections in one year that are not related to the use of antibiotics
• Recurrent pelvic inflammatory disease (PID)
• Abnormal Pap test or cervical cancer

Children with HIV often have different symptoms (for example, delayed growth or an enlarged spleen) than teens or adults.

Late stage

AIDS occurs during the last stage of infection with HIV. If HIV goes untreated, AIDS develops in most people within 12 to 13 years after the initial infection. With treatment for HIV, the progression to AIDS may be delayed or prevented.

After your immune system starts to weaken, you are more likely to develop certain infections or illnesses, called opportunistic infections. Examples include some types of pneumonia or cancer that are more common when you have a weakened immune system.

A small number of people who are infected with HIV are rapid progressors. They develop AIDS within a few years if they do not receive treatment. It is not known why the infection progresses faster in these people.