Acute diseases are diseases which last for short periods of time. An example of an acute disease would be the common cold.
Chronic diseases are diseases which can last for long periods of time. Some chronic diseases even last for the entire lifetime of the organism. An example of chronic disease would be asthma.
Infectious diseases are diseases that are caused by infectious agents such as viruses, bacteria, worms, etc. examples for infectious diseases include the common cold and AIDS. Infectious diseases can spread through – (i) insects such as mosquitoes, (ii) consumption of infected food.