"It's going to be a tougher and more labour intensive summer for those who are working this year," says Henrik Almkvist, chief doctor in Stockholm county.
Gothenburg faces similar shortages, primarily in psychiatric care, the accident and emergency wards and in surgery.
Umeå is missing nurses on the surgery wards and do not have enough staff to take care of all stroke patients.
Malmö also lacks staff but representatives tell Swedish Radio that they hope to offer the same level of care to patients throughout the summer.
The capital Stockholm usually runs on 80 percent capacity as medical staff go on summer vacation but will be forced to sink below that rate this year.
Union says situation could have been avoided
The Swedish Association of Health Professionals, the trade union that represents nurses, says its members fear this will affect patient care, according to a new survey.
"Patients will suffer and it affects our working environment. How are we supposed to find the strength to work under these conditions our entire lives?" asks chairperson Sineva Ribeiro.
"This year the students said they'd work the summer if they were properly paid. Their demands were not met and that's why we face shortages," she says.
Compensation for existing staff
"We are still trying to recruit staff, we are compensating people who have to move their holiday dates around, and we're adding US$75 for extra shifts in addition to overtime pay," says chief doctor Henrik Almkvist in Stockholm.