No need to panic!!
The question of residency rights has been a topic of discussion for months, however, a definitive decision has now been taken.
The Portuguese Government has been particularly reassuring to existing residents and confirmed that UK ex-patriots will still maintain their previous benefits, even in the event of a no-deal Brexit, however, applying for residence is recommended. Interior Minister Eduardo Cabrita recently announced that UK tourists or residents, particularly investors and even students, are welcome in Portugal all rights will be reciprocal with access to health care and social security post-Brexit and will similarly apply to the almost 500,000 Portuguese citizens in the UK: Other commitments to be introduced will be fast track lanes at airports, additional consular offices and continuing recognition of the UK driving licence. After the 31st of October 2019, and should a no deal Brexit be the outcome, those who can demonstrate residency before that date will be eligible to remain and have until 2021 to apply for residency and be issued with a 5 year permit, after 5 years an application for permanent residency can be applied and after 6 years Portuguese citizenship.