Like cancer cachexia, the etiology of HIV-associated wasting is multifactorial and not completely understood. Contributing factors may be decreased intake related to nausea, anorexia, mouth infections, or fatigue. Diarrhea and malabsorption of nutrients decrease nutrient availability. Opportunistic infections or malignancies may also contribute to altered metabolism and weight loss, although they are not the major cause of wasting in PLHA. Excessive production of cytokines has also been implicated in HIVassociated weight loss. Although the majority of weight loss currently seen in PLHA cannot be explained, impaired intake and altered metabolism may be at least partially responsible.