Rose Polge, 25, from Torbay, has not been seen since Friday evening. Her car was found in a car park near Ansteys Cove in Devon.
Police said it was "totally out of character" for the young woman and are concerned for her welfare.
More than 100 people have been involved in the search operation, including her boyfriend and family.
Devon and Cornwall Police, a Coastguard helicopter and search and rescue helicopter have assisted with the operation, as well as Teignmouth RNLI lifeboat, Devon and Somerset Fire and Rescue Service and Dartmoor Search and Rescue Team.
Torbay Hospital on-call Director Martin Ringrose said: "We are aware that one of our junior doctors is missing.
"Our thoughts are with her family and loved ones at this very distressing time.
"We will do whatever we can to support the authorities investigating her disappearance and searching for her, as well as providing support to her colleagues, who are anxious for her wellbeing."
A police spokesperson said: "We are searching for a missing person and we are extremely concerned for her welfare. The conditions have been rough since she was reported missing.
"We are working with the Coastguard and other agencies."
A statement released by UK Coastguard said they had been called to support the police operation at 6.20pm on February 12.
Torbay, Teignmouth and and Berry Head Coastguards have been involved in the search.
Police are appealing for the public to contact them with any information or sightings of Dr Polge.

Suppliers in England and Wales faced 106,693 complaints in 2014-15, a drop 13.4% compared to the previous year, the Consumer Council for Water said.
About 60% of gripes were about billing and charges, the figures showed.
The watchdog applauded the companies for their efforts, but said there was still room for improvement.
It called on suppliers to improve their service by providing "clear, accurate and timely" bills. It added that speed in fixing reported leaks was still a source of frustration for customers.
"We expect the water industry to continually try and improve its services to customers and many water companies deserve credit for rising to that challenge year after year," said Tony Smith, chief executive of the Consumer Council for Water.
"However, the gulf between the best and worst performers remains unacceptable."
Southern was the worst performing company for complaints per 10,000 connections, as it has been since 2012-13, although its complaint levels did fall by nearly 13% compared with the previous year.
"We are disappointed not to have made more progress on reducing complaints," said director Simon Oates.
"We have spent Â£13m to upgrade its billing system, which will help customers to manage their accounts online. Once this system has bedded in, we expect that we will see complaint numbers start to fall."
Four companies - Anglian Water, Affinity Water, Portsmouth Water and Hartlepool Water - recorded increases in complaints compared with the previous year.

Ms Boyd, who was elected to represent Castle ward in 2012, became the first woman to lead Stirling Council.
She is currently the youngest council leader in Scotland and one of only four women.
She said her decision not to seek re-election was not easy but that it was time to address "personal priorities."
She said: "I am incredibly proud of what Labour-led Stirling Council has achieved over the last five years and I will continue to devote my energy to securing a City Deal for Stirling and the wider region.
"The reason I am not seeking re-election is very straightforward. I made a full time commitment to the role of leading Stirling Council for the past five years and it's now time for me to address some personal priorities.
"The welfare of my young family has always come first and at this time the means of achieving that is the continuing development of my legal career."
She added: "I will miss my role in local government and working with councillors from across the political spectrum as well as council staff who are dedicated to delivering the best public services in very challenging times."
A major search operation is under way for a 25-year-old junior doctor who has gone missing.
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Complaints made to water companies have fallen for the seventh successive year, but are still dominated by worries about bills.
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The Labour leader of Stirling Council, Johanna Boyd, has announced that she will not be standing in next year's local government elections.