Tuberculosis (TB) Testing
Citizens of certain nationalities are required to be screened for Tuberculosis (TB) as part of their visa application process if they are coming to the UK for more than 6 months.
There is a list of the countries issued by UK Visas and Immigration (UKVI) , which shows where TB testing is a requirement. As a national of one of these countries, you are required to obtain a 'Clearance Certificate' from an accredited clinic.
You can read a more detailed overview of the test requirements outlined by UKVI.