Comorbidity is a term which is used to refer both to conditions beyond a primary medical condition of interest, and the consequences of interactions between multiple medical conditions. It is not uncommon for people to have multiple medical problems or diagnoses, and understanding how comorbidity works can be an important part of treatment. When something is said to be “comorbid,” it means that it is occurring in addition to something else.
Patients with cormorbidities can experience a variety of health problems. In addition to experiencing symptoms associated with each condition they have, they can also experience problems as a result of the interactions of the diseases. For example, someone with diabetes and cardiovascular disease could experience circulatory problems caused by the interactions of the two conditions, in addition to the actions of each condition independently.
Treating a patient with one or more comorbidities is challenging. Medications and treatments which are effective for one condition might exacerbate another, for example, or the approach to treatment might need to be adjusted to account for the patient's life expectancy. Using a system known as the Charlson comorbidity index, doctors can assign scores to the conditions the patient has and add them up to get an idea of the patient's expected lifespan. This information might be used when making decisions about treatment; for example, if a patient is likely to die of liver failure within six months, the costs of treating stomach cancer might not be worth it.
In psychiatry, cormorbidity is a common topic of discussion. Many people with mental illness have multiple diagnoses, reflecting the fact that their symptoms are varied and cannot be explained by a single diagnosis. Mental illness can also be a common problem in people with developmental disorders. Individuals with psychiatric comorbidities need treatments which address all of their diagnoses as a collective, rather than just looking at one. Treating depression alone, for example, will not be effective in a patient who also has an anxiety disorder.
Patients should discuss the implications of comorbidity with their doctors. They may need to take special care to address their conditions, or to observe precautions which other patients do not. Comorbidities should also be weighed when discussing treatment options, and patients should make sure that doctors are familiar with their complete medical history before discussing diagnosis and treatment, to ensure that errors are not made as a result of lacking access to important information about a comorbidity.