How do I know if I need antibiotics?

Antibiotics are used to kill or slow down bacteria proliferating in an organism. In other words, to treat a bacterial infection. But in case of a virus, antibiotics cannot be used as they are ineffectual on viruses. If a person is suffering from any bacterial infection, then he needs only antibiotics, otherwise not. Through tests and examination by a doctor, a person can know whether he is suffering from a viral infection, bacterial infection or some other type of infection, as the symptoms of almost every infection are similar. For antibiotics, the right dose and the right amount is prescribed by a doctor, otherwise, they can have various types of side-effects. In every type of infection, whether its bacterial or viral, extreme care is needed as most of the infections are deadly in nature, irrespective of their fatality rate.