I'm nearing the end of my US visa application process, and I had the mandatory medical exam last friday.
It consisted of:
A few forms that you have to fill out regarding your medical history, plus your signed permission for them to screen your blood for HIV/AIDS.
A fairly lengthy Q&A with the physician.
Height, weight and blood pressure recordings taken.
Fully disrobed checkover.
Three tubes of blood taken (for HIV/AIDS and TB screening).
Chest xray.
Immunisations, if required (I had to have a tetanus booster and an MMR, as my NHS vaccination sheet was so poorly written that the physician couldn't tell if i'd had the MMR or not. In that event, they have to assume you haven't had it and so give it to you there and then for a fee).
My BP was high, so the physician advised that I should see my GP and have him take the readings. He also wanted a letter from my GP stating what the retaken BP figure is, and details of any prescribed meds (if any). I faxed this over to the visa physician today, which now allows him to close my case and send his recommendations straight to the US Embassy.
It's pretty thorough.