The difference between taking azithromycin for 3 days and after taking it for 5 days is actually not significantly different, because azithromycin is a long-acting drug, which enters the body metabolism after taking it and can be maintained in the human blood concentration for more than 24 hours, that is, after taking azithromycin for 1 time, the blood concentration can reach the therapeutic effect for 1 day. After 3 days of azithromycin administration, the blood concentration in the body can last for more than 2 days, and it forms a stable value of blood concentration for 5 days, which is very effective against Mycoplasma, Chlamydia and broad-spectrum bacteria, and is very effective against pneumonia and bronchitis caused by Mycoplasma pneumoniae infection. Azithromycin is taken for 5 consecutive days, and the blood concentration is actually sufficient to reach therapeutic concentration. After 3 days of taking it, it has already reached an effective blood concentration that can last for 2 days, just adding another 2 days of doubled azithromycin intake, the blood concentration is enough to be effective against mycoplasma, chlamydia, and broad-spectrum bacteria, so you can choose both ways of taking it.