Patients with chronic underlying diseases, obesity, pregnant women, infants and the elderly are prone to serious and critical cases of influenza A (H1N1). Experts suggest that the above-mentioned people should reduce or avoid crowded places, avoid contact with people with flu-like symptoms, wear medical masks when going out, wash hands regularly and pay attention to personal cleanliness. If you have flu-like symptoms, you should not wait for the laboratory test results, but use Tamiflu antiviral drugs as soon as possible according to the actual situation.