Doctors in Preston sign 104 fit notes, on average, every day according to the latest NHS figures.
GPs working in the NHS Greater Preston CCG issued a total of 37,858 notes between July 2017 and June this year.
But the rules are to be changed to allow other health workers to sign people off sick, reducing the workload faced by doctors.
The Department for Work and Pensions says that it will legislate to allow other health professionals to certify people as unable to work.
The move has been welcomed by doctors' leaders, who say it will ease the pressure on GPs.
People in work need a fit note, previously called a sick note, if they are off work for more than seven days. Up to that point they can self-certify that they are unwell.
Across England, 5.7 million fit notes were handed out over the 12 months to the end of June.
A Department of Work and Pensions spokesperson said: "We want to reduce the burden on GPs and that’s why we intend to legislate for the extension of fit note certification to other healthcare professionals. We will work with the NHS on this.”
Professor Helen Stokes-Lampard, chair of the Royal College of GPs, said: “It is vital that a robust system is in place to ensure people are fit for work, and if they are not, then they have ready access to the appropriate care and services to improve their quality of life.
"At a time when our workload in general practice is escalating in both volume and complexity – and when patients are waiting longer and longer for appointments – we would certainly welcome exploring whether other highly-skilled clinical members of the practice team can share some of these responsibilities."
The British Medical Association said that if another health professional, such as a physiotherapist, was treating a patient, they should be able to certify fitness for work rather than additionally involving a doctor.
Dr Richard Vautrey, chair of the BMA GP committee, said: “At a time when admin has become increasingly burdensome in general practice, compounding existing workload issues, it makes perfect sense for the healthcare professional seeing the patient to issue fit notes where needed, removing the added layer of bureaucracy involved in getting it signed off by an individual GP.
In Preston, the average monthly rate of fit notes was 2,708 per 100,000 working age people registered with a GP. The highest rate was 3,695 in Halton, Cheshire. The lowest rate was 851 in Richmond, London.
The most common reasons that doctors signed people off work were mental and behavioural disorders, particularly stress, and muscoskeletal conditions, such as back problems.
Of the 37,858 notes signed over the 12 months in Preston, 4,946 were issued for mental health issues and 2,510 for back problems.
The number of fit notes signed in Preston from July 2017 to June this year is down on the previous 12 months, but this may be due, in part, to under-reporting in February caused by technical issues in gathering the data.
Despite being called fit notes, almost all of those issued classify people as unfit for work. This was the case for 94% of the notes handed out across the country.
However, fit notes are also used to advise patients and their employers on getting back to work. This includes recommendations for an employee to make a phased return, or work reduced hours or with limited duties.
Women were signed off sick more than men. They received 57% of the fit notes across England in the 12 months.