The risk of a serious cardiovascular event (heart attack or stroke) is doubled in the week following a serious respiratory infection, such as flu or acute bronchitis. This is according to a report in the European Heart Journal, submitted by London researchers. A large primary caregivers' database on over 2 million patients provided data on first-time cases of heart attack (over 11,000) or stroke (over 9,000), as well as on matched controls. Compared with the frequency in the month prior to the event, there was strong evidence of an increased frequency of both events in the 7 days following the infection. The risks were 2.1 times and 1.92 times greater for heart attack and stroke, respectively.

If this isn't enough to make up your mind about getting a flu shot every year, I don't know what will. And get your acute bronchitis (or any other severe respiratory infection) treated early and adequately. But a head cold or runny nose isn't a risk-raiser.