Mental illness is an "illness" of the "mind". Strange behaviour or having strange thoughts, which can be construed as "not normal" by others is generally referred to as an illness of the mind. Certain mental illnesses seem to be there from birth, quite popularly put into the category of "result of a birth disorder"; other "strange" or "abnormal" behaviour that develops during the life of a person.

People who are "affected" or display "illness of the mind" often have problems dealing with other people or leading what is called a "normal" life.

What is considered "mental illness" has changed over time. There are "halal"/"Permissible in Islam" cures/solutions to all the modern "mental illnesses" commonly faced by mankind as mentioned below:

1) Inability to:
   a) Control anger or rage for reasons that don't deserve such a response.
   b) Control recurrent, unwanted thoughts (obsessions) and/or repetitive behaviours that can cause physical and or emotional harm.
   c) Control the intake or refrain from taking Alcohol.
   d) Control one's wrong actions even if one knows them to be wrong.
   e)Stop obsessing about sex.
   e) Tell the difference between real and unreal experiences.
   f) Think logically; have normal emotional responses and behave normally in social situations.
   g) Overcome frustration with life and failures causing depression.
   h) Obsession about materialistic wants and desires.
2) Feel:
   a) Tired and listless.
   b) Like staying alone and not mixing with friends and family.
3) Having an intuition about being a victim of Black Magic or Witchcraft
4) Having suicidal thoughts and tendencies.
5) People vacillating between periods of good or irritable moods. "Mood Swings" between mania and depression.
6) Moving away from one's religion and faith.
7) Hearing sounds that others cannot.
8) Constant bickering/arguments and misunderstandings with people they care about.

Physical ill health:

1) Body pain with no permanent cure.
2) Suffering from sleeplessness/insomnia.
3) Migraines.