The spreading time can be a major difference between flu and Covid, because Covid spreads faster than flu. And most flu unless sever will not show muscle aches. The sudden loss of smell and taste even when nose is not blocked and no cough is a possible sign of Covid. Other symptoms are almost same for both covid and seasonal flu or common flu like fever, headache, cough, runny nose, blocked nose and body aches. So WHO suggests to observe for the fastness of spreading and severity in low immune persons for ruling out covid from flu. WHO also says that continue following covid rules such as wearing masks, maintaining social distance, washing hands and eating healthy diet to avoid spreading of covid further.