We have to start with two simple definitions. "Sex" is the basic biology. Chromosomes are usually clear on your male or femaleness even though, on occasion, the physical body is ambiguous. Gender is sometime we construct through our culture. These are the roles we give people depending on the way they present themselves to the world. Hence, an individual may have a clear biological sex but, because of gender reassignment surgery, present to the world as a member of the opposite sex. It's this type of confusion we address through the laws on equality and discrimination. With the repeal of the "don't ask, don't tell" rule in our military, the level of social acceptance for difference is steadily improving. Whether it will include the acceptance of the right to marry is hard to predict.
It takes years to build hospitals and train all the doctors and nurses to staff them. This means we have to start the planning process now because, as time moves on, there will be more women than men in our society. Thanks to the quality of the medical treatment they receive, they are outliving men. So looking ten, twenty and more years into the future, we will need a lot more resources devoted to the treatments relevant to women. The research suggests that there are two reasons for this gender imbalance. First, at a physical level, women seem more susceptible to pain. Second, psychologically, even if the first is wrong, women are able to admit to pain whereas men are expected to bear it with a smile. The result is a tide of women demanding treatment and an increasing shortage of healthcare resources.