Most  people are quite comfortable going about their everyday lives , peacefully, either trust into a routine , or completely destabilized for various reasons. The danger of being destabilized cannot be overemphasized.
The resulting effect of this situation, comes on very slowly, and usually undetected by the sufferer, and those around that person. This condition can go on to a very critical state  that could spur the person into external aggression and dangers to other people, as seen in recent times.  This condition whereby a person behaves out of the norm, is called mental illness.

A mental illness is a disease that causes mild to severe disturbances in thought and/or behavior, resulting in an inability to cope with life’s ordinary demands and routines.
Mental health problems may be related to excessive stress due to a particular situation or series of events. As with cancer, diabetes and heart disease, mental illnesses are often physical as well as emotional and psychological. Mental illnesses may be caused by a reaction to environmental stresses, genetic factors, biochemical imbalances, or a combination of these. With proper care and treatment many individuals learn to cope or recover from a mental illness or emotional disorder.

Mental illness refers to a wide range of mental health conditions — disorders that affect your mood, thinking and behavior. Examples of mental illness include depression, anxiety disorders, schizophrenia, eating disorders and addictive behaviors.
Many people have mental health concerns from time to time. But a mental health concern becomes a mental illness when ongoing signs and symptoms cause frequent stress and affect your ability to function. A mental illness can make you miserable and can cause problems in your daily life, such as at school or work or in relationships. In most cases, symptoms can be managed with a combination of medications and talk therapy (psychotherapy).

Warning Signs:
• It is especially important to pay attention to sudden changes in thoughts and behaviors. Also keep in mind that the onset of several of the symptoms below, and not just any one change, indicates a problem that should be assessed. The symptoms below should not be due to recent substance use or another medical condition.
In Adults, Young Adults and Adolscents:
• Confused thinking
• Prolonged depression (sadness or irritability)
• Feelings of extreme highs and lows
• Excessive fears, worries and anxieties
• Social withdrawal
• Dramatic changes in eating or sleeping habits
• Strong feelings of anger
• Strange thoughts (delusions)
• Seeing or hearing things that aren’t there (hallucinations)
• Growing inability to cope with daily problems and activities
• Suicidal thoughts
• Numerous unexplained physical ailments
• Substance use

In Older Children and Pre-Adolescents
• Substance use
• Inability to cope with problems and daily activities
• Changes in sleeping and/or eating habits
• Excessive complaints of physical ailments
• Changes in ability to manage responsibilities – at home and/or at school
• Defiance of authority, truancy, theft, and/or vandalism
• Intense fear
• Prolonged negative mood, often accompanied by poor appetite or thoughts of death
• Frequent outbursts of anger

In Younger Children
• Changes in school performance
• Poor grades despite strong efforts
• Changes in sleeping and/or eating habits
• Excessive worry or anxiety (i.e. refusing to go to bed or school)
• Hyperactivity
• Persistent nightmares
• Persistent disobedience or aggression
• Frequent temper tantrums

What are the symptoms?
Signs and symptoms of mental illness can vary, depending on the disorder, circumstances and other factors. Mental illness symptoms can affect emotions, thoughts and behaviors.
Examples of signs and symptoms include:
• Feeling sad or down
• Confused thinking or reduced ability to concentrate
• Excessive fears or worries, or extreme feelings of guilt
• Extreme mood changes of highs and lows
• Withdrawal from friends and activities
• Significant tiredness, low energy or problems sleeping
• Detachment from reality (delusions), paranoia or hallucinations
• Inability to cope with daily problems or stress
• Trouble understanding and relating to situations and to people
• Alcohol or drug abuse
• Major changes in eating habits
• Sex drive changes
• Excessive anger, hostility or violence
• Suicidal thinking
• Sometimes symptoms of a mental health disorder appear as physical problems, such as stomach pain, back pain, headache, or other unexplained aches and pains.

Possible causes
1. Mental illnesses, in general, are thought to be caused by a variety of genetic and environmental factors:
2. Inherited traits. Mental illness is more common in people whose blood relatives also have a mental illness. Certain genes may increase your risk of developing a mental illness, and your life situation may trigger it.
3. Environmental exposures before birth. Exposure to environmental stressors, inflammatory conditions, toxins, alcohol or drugs while in the womb can sometimes be linked to mental illness.
4. Brain chemistry. Neurotransmitters are naturally occurring brain chemicals that carry signals to other parts of your brain and body. When the neural networks involving these chemicals are impaired, the function of nerve receptors and nerve systems change, leading to depression.

Improving mental health
1. Value yourself:
Treat yourself with kindness and respect, and avoid self-criticism. Make time for your hobbies and favorite projects, or broaden your horizons.  Do a daily  crossword puzzle, plant a garden, take dance lessons, learn to play an instrument or become fluent in another language.
2. Take care of your body:
Taking care of yourself physically can improve your mental health. Be sure to:
Eat nutritious meals
Avoid cigarettes —
Drink plenty of water
Exercise, which helps decrease depression and anxiety and improve moods
Get enough sleep. Researchers believe that lack of sleep contributes to a high rate of depression in college students.
3. Surround yourself with good people:
People with strong family or social connections are generally healthier than those who lack a support network. Make plans with supportive family members and friends, or seek out activities where you can meet new people, such as a club, class or support group.
4. Give yourself:
Volunteer your time and energy to help someone else. You’ll feel good about doing something tangible to help someone in need — and it’s a great way to meet new people
5. Learn how to deal with stress:
Like it or not, stress is a part of life. Practice good coping skills: Try One-Minute Stress Strategies, do Tai Chi, exercise, take a nature walk, play with your pet or try journal writing as a stress reducer. Also, remember to smile and see the humor in life. Research shows that laughter can boost your immune system, ease pain, relax your body and reduce stress.
6. Quiet your mind:
Try meditating, Mindfulness and/or prayer. Relaxation exercises and prayer can improve your state of mind and outlook on life. In fact, research shows that meditation may help you feel calm and enhance the effects of therapy.
7. Set realistic goals:
Decide what you want to achieve academically, professionally and personally, and write down the steps you need to realize your goals. Aim high, but be realistic and don’t over-schedule. You’ll enjoy a tremendous sense of accomplishment and self-worth as you progress toward your goal. Wellness Coaching, free to U-M students, can help you develop goals and stay on track.
8. Break up the monotony:
Although our routines make us more  efficient and enhance our feelings of security and safety, a little change of pace can perk up a tedious schedule. Alter your jogging route, plan a road-trip, take a walk in a different park, hang some new pictures or try a new restaurant.
9. Avoid alcohol and other drugs:
Keep alcohol use to a minimum and avoid other drugs. Sometimes people use alcohol and other drugs to “self-medicate” but in reality, alcohol and other drugs only aggravate problems
10. Get help when you need it:
Seeking help is a sign of strength — not a weakness. And it is important to remember that treatment is effective. People who get appropriate care can recover from mental illness and addiction and lead full, rewarding lives.

Risk factors
Certain factors may increase your risk of developing mental health problems, including:
Having a blood relative, such as a parent or sibling, with a mental illness
Stressful life situations, such as financial problems, a loved one’s death or a divorce
An ongoing (chronic) medical condition, such as diabetes
Brain damage as a result of a serious injury (traumatic brain injury), such as a violent blow to the head
Traumatic experiences, such as military combat or being assaulted
Use of alcohol or recreational drugs
Being abused or neglected as a child
Having few friends or few healthy relationships
A previous mental illness
Mental illness is common. About 1 in 5 adults has a mental illness in any given year. Mental illness can begin at any age, from childhood through later adult years, but most begin earlier in life.
The effects of mental illness can be temporary or long lasting. You also can have more than one mental health disorder at the same time. For example, you may have depression and a substance use disorder.

Complications
• Mental illness is a leading cause of disability. Untreated mental illness can cause severe emotional, behavioral and physical health problems. Complications sometimes linked to mental illness include:
• Unhappiness and decreased enjoyment of life
• Family conflicts
• Relationship difficulties
• Social isolation
• Problems with tobacco, alcohol and other drugs
• Missed work or school, or other problems related to work or school
• Legal and financial problems
• Poverty and homelessness
• Self-harm and harm to others, including suicide or homicide
• Weakened immune system, so your body has a hard time resisting infections
• Heart disease and other medical conditions

Prevention
There’s no sure way to prevent mental illness. However, if you have a mental illness, taking steps to control stress, to increase your resilience and to boost low self-esteem may help keep your symptoms under control.
• Pay attention to warning signs. Work with your doctor or therapist to learn what might trigger your symptoms. Make a plan so that you know what to do if symptoms return. Contact your doctor or therapist if you notice any changes in symptoms or how you feel. Consider involving family members or friends to watch for warning signs.
• Get routine medical care. Don’t neglect checkups or skip visits to your health care provider, especially if you aren’t feeling well. You may have a new health problem that needs to be treated, or you may be experiencing side effects of medication.
• Get help when you need it. Mental health conditions can be harder to treat if you wait until symptoms get bad. Long-term maintenance treatment also may help prevent a relapse of symptoms.
Take good care of yourself. Sufficient sleep, healthy eating and regular physical activity are important. Try to maintain a regular schedule. Talk to your health care provider if you have trouble sleeping or if you have questions about diet and physical activity.