As a British Citizen If you move to England permanently or return to live in England permanently, you're entitled to free NHS hospital treatment.
Like other UK residents, you'll have to pay some NHS charges (for example, for prescriptions), unless you are exempt from these.
Different rules apply if you're visiting England temporarily.
If you move to the UK, you will not be charged for NHS hospital treatment from the date that you arrive as long as: you intend to live permanently in the UK, and you have the right to live permanently in the UK. As an expat that should not be problem
You'll be expected to prove that you meet these requirements.
Your spouse or civil partner and children under the age of 16 (under 19 if in full-time education) are also exempt from these charges if they live with you permanently.
Hospitals are responsible for checking who should pay for NHS hospital treatment.
The hospital will ask you for evidence to prove that you intend to live in the UK permanently. The documents that you provide will depend on your circumstances.
Examples could include: documents showing the sale of goods or property overseas, receipts showing shipping of goods to the UK, evidence that you're looking for work, evidence that you have bought property in the UK or have rented a property, papers that show you've applied for benefits, evidence that your children are attending school in the UK
The hospital will also ask you for evidence to prove that you're legally entitled to live in the UK eg your British passport.
You'll have to pay statutory NHS charges such as prescription charges, unless you are exempt.
Under current rules anyone can register with a GP practice in England and receive free primary care. A GP practice can only refuse an application to join its list of NHS patients where it has reasonable grounds for doing so: for example, if their lists are closed to new patients, the applicant lives in a different practice's boundary area, or in other rare circumstances.
Once registered as a NHS patient, primary care services provided by a GP practice are free, but secondary care services (such as a referral to a specialist) are not free simply because you're registered with a GP.
If you have problems registering with a GP, you can try a different practice or ask for the assistance of the local clinical commissioning group.
If you have problems getting an appointment, you can try a walk-in centre or GP-led health centre. Registration is not required and patients do not need an appointment. Most centres are open 365 days a year and outside office hours.
Regardless of your residential status you're entitled to free emergency NHS treatment.
You will want to get an NHS number to register with a GP. Follow this link http://www.connectingforhealth.nhs.uk/systemsandservices/nhsnumber/staff/history/nhsnumberpatinfo.pdf for a leaflet on finding out your NHS numbver or getting a new one.
I hope this answer is helpful but please feel free to ask further questions