Despite the growing number of adult transgender and gender diverse (TGD) patients seeking health services, there are many unknowns regarding how routine screening recommendations should be applied to TGD persons receiving gender-affirming hormone therapy (GAHT). Patients taking GAHT may have disease risks that differ from what is expected based on their sex assigned at birth or affirmed gender identity. We discuss two patient cases, one transgender man and one transgender woman who present for routine medical care, to review several conditions that may be impacted by the hormones utilized in masculinizing and feminizing GAHT and for which screening recommendations are available for TGD adults: cardiovascular risk factors, osteoporosis, breast cancer, cervical cancer, and prostate cancer. We reviewed the TGD-specific screening recommendations from several major medical organizations and programs and found them to be largely based upon expert opinion due to a lack of evidence. The goal of this narrative review is to assist healthcare professionals in counseling and screening their TGD patients when and where appropriate. Not all TGD adults have the ability or need to receive routine medical care from a specialized TGD health clinic; therefore, it is essential for all healthcare professionals involved in routine and gender-affirming care to have knowledge about these conditions and screenings.