Changes or abnormalities in heartbeat rhythm may be experienced with flu, which indicates a possible problem with the heart muscles.3 Studies have suggested that people with heart disease are less likely to have a heart attack if they have a flu jab, compared to those that develop flu.4
For people with chronic kidney disease, contracting flu can make their condition worse.5
For people with liver disease, contracting flu may increase the likelihood of developing complications or worsen their condition.6
Some examples of these conditions include chronic heart failure, high blood pressure with heart complications, chronic kidney failure, hepatitis, liver cirrhosis.