NEW YORK: Tanya Walker had lung cancer and was coughing up blood, but she says her emergency room doctor kept asking about her genitals.

"It seemed like they weren't going to treat me unless I told them what genitals I had," Walker, a 53-year-old transgender woman, activist and advocate, said about her 2013 experience in a US Department of Veterans Affairs hospital in New York. "I felt cornered."

She experienced a stigma shared by many transgender people. The same rejection they confront at home and in society can often await them in the doctor's office, where many report being harassed, ridiculed or even assaulted.

Transgender issues have soared into the US public consciousness since the US Supreme Court ruled last year that same-sex marriage was a constitutional right. With that final item on the gay and lesbian agenda fulfilled, gender minorities turned their attention to unrealised transgender civil rights.

Society is gradually learning the basics of gender identity, but the medical profession has been slow to adapt, according to leaders in transgender medicine, transgender advocates and patients.

About 30 percent of transgender patients report delaying or not seeking care due to discrimination, according to a report published in the June edition of the journal Medical Care. One in four say they were denied equal treatment in healthcare settings.

Walker said the doctor who was distracted by her sex organs misdiagnosed her lung ailment as tuberculosis. He gave her antibiotics and sent her home. Three months later she discovered she had lung cancer, Walker said, though she is now cancer-free.

Some doctors acknowledge their profession is woefully out of date.

"We have a lot to apologise for in the medical community. Our treatment of transgender people has been abhorrent," said Dr. Aron Janssen, founder and director of the gender and sexuality service at New York University Langone Medical Centre.

"The medical world is very far behind. It is a conservative organisation. Things are slow to move," said Janssen, who only takes new patients who are transgender.

Transgender people, who by a UCLA Williams Institute estimate account for 0.6 percent of the population, or 1.4 million Americans, face acute medical needs. They have higher rates of preventable disease, substance abuse, suicide attempts and mental health issues than the general population.

Transgender patients whose healthcare providers were uneducated on transgender issues were four times more likely to delay needed care, according to the June report in Medical Care by Kim Jaffee and Deirdre Shires of Detroit's Wayne State University and Daphna Stroumsa of Detroit's Henry Ford Hospital.

Simply by asking questions, doctors who lack knowledge on transgender issues "can unwittingly create an atmosphere of disapproval for transgender patients," their research found.

Transgender patients say they are routinely "misgendered" and referred to by their birth names and gender, even if their identity documents have been legally changed.

Jay Kallio (61), a transgender man, had a lump in his breast checked out in 2008. He said his main doctor, who he declined to identify, never called back with the results of a biopsy and he only discovered he had aggressive breast cancer when a radiologist happened to check up on him weeks later.

Kallio did eventually speak to the primary doctor.

"He immediately said, 'I have a problem with your transgender status.' He said, 'I don't even know what to call you,'" Kallio said.