About 50 percent of gay men are not. The main reason is fear. How do you come out to your doctor if you suspect they might be homophobic? Will he or she out you to your family and co-workers? Will they deny you care, ask you to see another doctor, or give you inferior care? These are real fears, after all. But fear has no place in a doctor's office. The consequences are too great.
If your doctor does not know you are gay, he is not going to ask you the right questions, screen for.. conditions you are at risk for, and in some cases not provide the right treatment. I spend a lot of time talking about Safe Sex 101 to new patients. Unfortunately, few straight doctors are going to know the specifics of safe sex as applied to gay men. And many are not well-versed in certain screenings and vaccines because they do not really apply to straight men.
For example, gay men are at a higher risk for anal cancer. If your doctor does not know you are gay, he might not recommend, as we do, that you receive Gardasil & Gardasil-9 vaccines. These vaccines protect against HPV (the virus that causes anal cancer). Also gay men should receive Hepatitis A&B vaccines, due to the increased level of exposure.