I always see all my own medical data. Not that I can understand it completely, not being medically trained, but I have a good idea. And I ask questions. Plus I see my husband's full medical data, as well.
As his legal Health Car Surrogate it can't be denied to me. And he has the same exact authority over me, and he can examine all my medical records, too. Also to make decisions about each other's care, when we ourselves cannot.
I've already had to do that with my husband, approving his triple bypass heart surgery. It was my decision, not his. And authorizing a radical procedure to successfully save his right leg another time, which had gone into gangrene.
Yah know we're partners, and need to know these things, especially in a medical emergency. And we're had them, as I've noted! We were right by each other's side in the ER, when one of us has had a medical crisis.
That's why I planned ahead, as soon as we got together, and had all the legal instruments drawn. I recommend other guys living together do the same.
You can always revoke them, tear them up, if you split. But you can't create them after one of you is unconscious in the hospital. And you get banned to the hospital's general waiting lobby, unable to even see him because you have no legal status. Think about it.