Mental Health vs Mental Illness
Though these terms are often used interchangeably, they represent different concepts. Mental Health is defined as :
"...our mental well-being: our emotions, our thoughts, and feelings, our ability to solve problems and overcome difficulties, our social connections, and our understanding of the world around us." (here to help bc)
In other words, mental health is when you feel like you. Its when you can balance the various aspects of your life including the physical, mental, emotional and spiritual . On the other hand, mental illness is defined as :
"A mental illness is an illness that affects that way people think, feel, behave, or interact with others. There are many different mental illnesses, and they have different symptoms that impact peoples’ lives in different ways." (here to help bc)
The two often intersect. Mental health and mental illness are ever-changing. One day you might be feeling stressed or feeling a bit down. If you have good mental health, that does not mean you have to be happy all the time, it is about knowing how to live despite feeling a bit down. 
It is also possible to have good mental health, yet still, be diagnosed with a mental illness. At the same time, it is possible to have poor mental health but no mental illness. How you feel can change day to day, it is just like any other health problems.
Myth vs Reality
Myth: Mental Illnesses are not real illnesses
Reality: Mental illness are real illnesses. They do not go away on their own and have treatments available to help. As said by CMHA: "When someone breaks their arm, we wouldn’t expect them to just “get over it.” Nor would we blame them if they needed a cast, sling, or other help in their daily life while they recovered."
Myth: People don't recover from mental illnesses.
Reality: People with mental illnesses can and do recover from mental illnesses. There are a variety of treatments, services, and supports available for those with mental illnesses that can positively benefit them. Many people who have mental illnesses lead healthy and productive lives. Even if someone experiences mental health longterm they still are able to learn how to manage their symptoms .
Myth: Children and teenagers don't experience mental illnesses.
Reality: One in five children and teenagers have a mental illness. Though they might show up differently, there are mental illnesses that show during a person's youth. Five out of six of these children won't get the help they need. Early identification can help.
Myth: Mental Illness will never affect me.
Reality: By the age of 40, around fifty percent of the population will have had or have a mental illness. For more facts about who is affected, how common it is and its impact check out CMHA's page: Fast Facts about Mental Illness.
Websites to Learn More about Mental Health
Mental Health Quick Facts:
More from AMHI: