A hormonal problem called androgen deficiency is commonly seen in chronic illnesses with advanced stages. Blood amounts of androgen may drop as a result of the illness, as a cause, or as both. Low levels of androgen may indirectly impact the severity of the illness and may exacerbate common symptoms like fatigue or muscle weakness in heart failure. A novel treatment option for heart failure symptoms has recently been proposed: androgen replacement therapy. Placebo-controlled pilot studies have revealed a modest improvement in physical performance. However, testosterone replacement in elderly patients carries some risks, and it is unknown what the benefit-risk ratio of this adjunctive therapy.