Annual checkups are just that. 1) Body weight measurements. 2) The doctor talking to you about whether you have any medical or life concerns. 3) The doctor sharing advice on diet improvements, smoking improvements, exercise plans, including providing resources for them. 4) Recommended screenings based on age. 5) 1-2 vials of blood to get basic health information such as glucose levels, vitamin levels, etc. 6) Urine samples are only required if you're sexually active with multiple partners to screen for STDs and is completely optional.

That's been my experience. Through the annual physical I've been able to handle several minor issues, which have materially improved my life, and identified a major diagnosis that goes undiagnosed in the majority of people throughout their lives, and leads to them living significantly worse lives than they would have otherwise. By identifying it early, I have a chance for a much better lifestyle, and reducing the odds of an early death greatly.