IMMUNOSUPPRESSED - A decline in the functioning of the immune system. This condition may result from primary infection (HIV infection), genetic disease (e.g. cystic fibrosis), or be associated with chronic illness (heart, lung, or kidney disease), diabetes, and cancer. Some medications such as corticosteroids, or treatment with chemotherapeutic agents can also cause immunosuppression as a side effect. Many experts feel advanced age alone contributes to some degree of relative immunosuppression.