Nearly one in three Covid-19 patients ages 65 and older (32 percent) had at least one new or persistent medical condition in the months following their illness, according to a new study in BMJ that used the insurance records of people in a large Medicare Advantage program. That compares to about one in five people (21 percent) in that same period who were not infected with SARS-CoV-2, the virus that causes Covid.

The conditions for which patients commonly sought medical care included respiratory failure, cardiac problems (notably heart rhythm disorders), blood-clotting disorders, neurological problems (such as memory difficulties, dementia, and stroke), kidney injury, diabetes, hypertension, and anemia, as well as fatigue and mental health issues. Patients who had severe Covid requiring hospitalization were at highest risk of developing post-Covid medical problems, while those 75 and older had a greater risk of developing neurological conditions in particular.

The long-term effects of Covid are actively being investigated, but this study is one of the few to look specifically at older adults in the general population, including those not hospitalized for Covid. A limitation of the study is that some of the post-Covid conditions diagnosed, such as hypertension, may have been due to increased medical attention after SARS-CoV-2 infection and not actually new ailments triggered by the virus.