Being physically challenged offers all sorts of challenges that can be exacerbated in unfamiliar situations. This is especially true for people traveling or living abroad. Despite these difficulties, many people with physical handicaps are able to travel and live anywhere they want.
Transportation is one of the most difficult problems to overcome. From uneven sidewalks, to the lack of elevators to inadequate seating, moving around a foreign country can be especially difficult.
Elevators are an invention of the developed world. Many places throughout the world can only be accessed by stairs.
Hotels and theaters may have limited or non-existent handicapped facilities.
Further alienation from the place and people you are traveling among.
The biggest obstacle to get over, is the obstacles in the mind. Try not to view these as insurmountable issues, but problems to figure out.
Research before you go. Obviously, developing nations have the most issues for the disabled, but challenges are everywhere. Before you show up at an appointment- call ahead and confirm you can access the office. When reserving transportation or entertainment tickets, ask about the venue or services and make sure it is accessible. Special discounts may also be offered. Check on hotel facilities when reserving.
Luckily there are many excellent resources in countries that offer a difficult environment. Looking up "physically disabled travel in ________" usually results in very helpful travel agencies and groups. You can also network with other expats on forums to find common problems and solutions.
Always feel free to ask for help. Many people are not actively prejudiced, but just don't have proper facilities.
If you use special equipment like a wheelchair, keep it fully serviced to avoid problems. Also- find a local repair or medical supply store before you have an issue so if anything comes up you're ready. Make sure you have travel/medical insurance to cover costs.
Champion progress. By being a positive model of physical limitations, you can bring a face to the difficulties you encounter and put pressure on the powers that be to improve facilities.