If you have HIV or AIDS, it's important to receive early medical care from a doctor with experience in this field. Knowledge of AIDS and how to best treat the disease is constantly evolving, so the doctor you choose should be aware of all the latest research. Primary medical care is likely to involve several strategies. One of the most important is fighting opportunistic infections. These infections, which prey on a weakened immune system, are a major health threat to AIDS patients; preventing or delaying them can extend your life. Doctors may prescribe antibiotics in advance, before infection occurs. You may also be advised to make lifestyle changes, on the theory that this could strengthen your immune system. Some scientists feel that alcohol, recreational drugs, and too much ultraviolet radiation may impair your immune function, by decreasing your levels of glutathione (glue-tuh-THIGH-own). It appears that patients with higher amounts of glutathione survive longer. Another component of your care is drug therapy. The treating physician should be knowledgeable on the most effective combinations of AIDS drugs, and know when to alter treatment in response to the amount of the virus in your blood. To judge the medication's effectiveness, your level of infection-fighting 'T-cells' must also be calculated. For more information about primary medical care for HIV or AIDS, consult an AIDS specialist.