The healthcare in the United Kingdom is provided through the NHS (National Health Service). The UK provides all its citizens and permanent residents with free public healthcare which covers pretty much every medical need of the patients. However, people can also choose to have private health insurance in order to access services faster and more efficiently at times.
The private healthcare branch in the UK is relatively small when compared to other European countries, because the National Health Service in the country is fed through taxation which means the entire population collectively funds the NHS. The NHS of each region within the UK has minimal structural differences but the majority of the service is the same. In England, the NHS is under the authority of the Department of Health. According to the 2018 Euro Health Consumer Index, the UK stands in the 16th spot.
As mentioned before, the National Health Service in the UK is free and accessible for each citizen and resident in the region, including expats. In addition, EEA (European Economic Area) citizens and Swiss citizens can benefit from the NHS in the UK through their EHIC (European Health Insurance Card). The European Union member state citizens also have advantages in the UK when getting service from the NHS, but these attributes of the NHS are probably going to change due to Brexit.
Once individuals get permanent residence in the UK, they have the same status as an EU or EEA or Swiss citizen have in the region. It means that they get free access to the NHS as British citizens do. Temporary residents also hold rights to access emergency treatment and family planning services. Although these services are free of charge for temporary and permanent residents alike, for other services, temporary residents have to have health insurance.
One additional fact is that if the original country of the resident and the UK have reciprocal healthcare agreements, they might get free access to the NHS without any extra payment. However, if the countries do not have an agreement, any visitor who remains in the UK for more than 6 months has to pay a fee called a health surcharge that costs between 150 to 200 pounds. Once this fee is paid, the individual can freely access to the NHS as citizens do, if not, any service used costs 150 per cent of the standard fee.