The fact several Scottish hospitals have been virtually full this week, forcing hundreds of patients to be cared for on the wrong wards, is not a good sign; particularly not when you acknowledge the fact this year's winter weather has so far been mild and seasonal viruses such as flu have been at low levels.

One is tempted to wonder how bad things might otherwise have been in our hospitals over the festive period, or might yet become, if conditions worsen.

The number of patients required to "board" (being accommodated on wards that are not the right one for their condition) is already concerning.

Dr Neil Dewhurst of the Royal College of Physicians of Edinburgh describes the latest figures as worryingly and unacceptably high.

The Herald has previously reported on high levels of boarding in children's hospitals; and we know from previous studies that the risks attached to being in hospital are higher for patients on the wrong ward.

Boarding comes with a greater risk of death, patients are likely to stay in hospital for longer and are more likely to have to be readmitted after they leave.

It is likely nursing staff will be less able to give their best when treating ailments outside their usual specialism. Meanwhile, some doctors talk of the "safari round" as they try to track down patients who should be kept together for specialist treatment but are instead dispersed among wards in large hospitals.

We know, at least partly, what lies behind the situation: difficulties in discharging patients to their homes or suitably supported placements in the community.

Bed-blocking , or delayed discharge in the official jargon, is still with us. Some hospitals have difficulty sending patients home when their immediate health needs have been met because of a lack of resources for care in the community.

In some places, such as Edinburgh, temporary closure of private care homes for the elderly which are not meeting inspection standards has added to the pressure. Other reasons include the significant cuts to bed numbers since 2007, staff shortages and communication failings.

What is clear is the pressures on NHS hospitals at peak periods are not diminishing, not least because of the increasing elderly population which already make up the majority of hospital patients. The best response is still unclear. That is why The Herald has been calling for a fundamental review of beds and capacity in the NHS as part of our Time for Action campaign.

This review is needed to assess how personal, residential and community care provision must grow to meet the needs of Scotland's ageing population.

It should also look at whether resources in the community are adequate for a policy that increasingly depends on supporting elderly patients who end up in hospital to return to their own homes.

Crucially, it must look at how best to ensure patients can be offered appropriate beds, on the right wards, with the correct staff at the right time.