The UK Health System
The NHS is the equivalent of Australia's Medicare. As a visitor to the country you will need to use your National Insurance Number to access medical care. But unfortunately accessing the health system isn’t as easy as dropping into your local medical centre.
To see a doctor you need to make an appointment to register at that particular surgery. This involves visiting the surgery’s nurse for a general check up. Once you have registered you can make an appointment to see a doctor at that surgery.
The problem with this system is: if you take a day off work sick and but have not registered with a surgery you need to call to make an appointment to register, which may take a couple of days, and then after you have registered, can make an appointment to see a doctor, which may take another couple of days. So, it's a good idea to register with your local doctor as soon as you land in London.
The alternative to visiting the local medical centre or doctors' surgery is the NHS Walk-in Centres. These are generally located in the cities hospitals and are used for illnesses that are relatively urgent. However, the average wait in an NHS Walk-in Centre is approximately 1½ to 2 hours.
For more information visit the NHS website: http://www.nhs.uk/