Having more than one health problem is more common than we think and potentially deadly. Almost one in every four of us has two or more health conditions. With each additional disease morbidity, mortality and polypharmacy increases.

Some think multimorbidity can be cured by focusing on the whole patient. Research shows the opposite.

Multiple health problems in one patient can lead to further health problems such as uncontrollable pain and depression. When patients are prescribed at least three drugs for different conditions, they very often get sleeping tablets and painkillers as well.

Some think multiple health problems can be cured by minimizing the uncoordinated care that comes with trying to deal with a number of health problems at once and that the focus should be on the whole patient and not on the individual health problems.

Research shows the opposite. Prioritising one condition over another can ease the burden of everyday management.

This is the basis of the sequential medicine we practice today. We deal with more than one problem by assigning relative severity and urgency to each problem and treating them serially. For example, cancer is very serious but delaying treatment by one week probably doesn’t make any difference to the final outcome. Whereas delaying treatment for appendicitis, even by a few hours, can be deadly. So the appendix comes out first.

It also works well when one health problem causes another in a well researched pattern. For example, we know a lot about the relationship between obesity, diabetes and heart disease. Clinicians who deal with these patients are skilled in managing weight, lipids and sugar within a set sequence.

Unfortunately, adequate treatment of well described constellations of conditions is in the minority. Most care of co existent morbidity is difficult, especially when sequencing and severity is not known or waxes and wanes. For example, what comes first – obesity or osteoarthritis of the knees? Do patients get fat because it is too painful to walk/exercise or does the excess weight cause the knee joints to disintegrate. What should be dealt with first and as a priority? Painkillers or diet? When should these priorities change?  Even more difficult still is making these decisions in real time where no link can be made between co existing diseases, such as with multiple sclerosis and diabetes.

Competing disease priorities which are subject to flux require difficult decisions about priorities and even tolerance of less than optimal outcomes. We have yet to find a way forward in this complex area.

A start would be to raise the profile of multimorbidity both in research and practice. All interventional research projects should be required to assess the impact of multimorbidity on their hypotheses and projected outcomes.  All our health professionals should undergo specific training in multimorbidity – not just those traditionally involved like GPs.