Accident & Emergency units across the county are warning of long waits as they experience high demand.
Wigan's A&E unit, which is used by many people in the Chorley area since Chorley's A&E closed at nights, has warned of high demand and long waits.
Meanwhile North West Ambulance Service said it has been inundated with calls over the Christmas period, and it is understood that ambulances have been diverted from Preston to Blackburn, as Royal Preston Hospital's A&E struggled to cope with demand.
NHS bosses have appealed to patients to only use emergency services if they really need them, and try other options to treat seasonal illnesses such as colds, flu and sickness bugs.
A spokesman for North West Ambulance Service said: "Between December 22 and December 27 we received a whopping 28,019 calls to 999. Please make the right call and leave the lines open for those who really need them."
The A&E unit at Wigan Infirmary has also experienced high demand over the last 24 hours. A spokesman said: "A&E is extremely busy today. Patients will be seen in order of clinical priority; those who come to A&E can expect to wait. Remember there are alternatives, including GP out-of-hours services, walk-in centres, pharmacists and the NHS 111 line."
No-one from Lancashire Teaching Hospitals Trust - which runs Preston and Chorley hospitals - was available to comment, but ambulance crews reported being diverted from Preston to Blackburn over the weekend, as the A&E staff struggled to cope with the numbers of patients."
At the start of the winter, local NHS bosses appealed to people to make sure they were going to the right places for emergency services.
Denis Gizzi, Chief Officer of Chorley and South Ribble and Greater Preston clinical commissioning groups said: “With unprecedented numbers of patients accessing NHS services, it’s more important than ever that NHS organisations and members of the public work together to make the best use of available services.
“A number of GP practices in our area are offering additional evening and weekend appointments, and patients should contact their practice for details.
“We are also supporting healthcare providers to ensure that people are treated in the most appropriate place for their need.”
Karen Partington, Chief Executive of Lancashire Teaching Hospitals NHS Foundation Trust, said: “We are taking a wide range of actions over the busy winter period so that patients receive safe and timely care, and our hard-working staff are supported.
“We have invested in our frailty service which provides early comprehensive geriatric assessment to find appropriate alternatives to hospital admission for older patients. The team also works closely with older patients to reduce the length of time they spend in hospital, and to facilitate speedier recovery from surgery.
“Additional clinics have been set up to provide prompt emergency treatment for patients with respiratory, gastroenterology and cardiology conditions. More treatment such as intravenous fluid therapy is being provided in people’s own homes so they don’t need to come into hospital.
“Additional doctors have been employed to help us care for the higher number of medical patients in hospital over winter, so they’re reviewed frequently and delays in treatment are prevented. We have secured an extra ambulance over winter to transfer people who have been discharged, which will relieve pressure on NWAS and free up beds quicker.
“Families and carers can support hospital staff during the winter by making arrangements to transfer their elderly relatives to care homes promptly when their hospital treatment concludes, so we can swiftly admit patients who need urgent care.
“Our staff are doing everything they can to provide the highest standards of care and treatment during this very busy period. Many are working extra shifts to provide services seven days a week, and lots of staff are providing additional support on the wards. On behalf of our board and our patients I wish to thank them for their continued commitment, effort and unwavering compassion.