Mental illness is also known as a mental health disorder. It refers to a wide range of mental health conditions – disorders that are affecting your behavior, thinking, and mood. Some examples include addictive behaviors, eating disorders, schizophrenia, anxiety disorders, and depression.
It is normal for people to have a mental concern from time to time. But, the mental health concern becomes a mental illness when the ongoing signs and symptoms are causing frequent stress and they can affect your ability to function. Mental illness can make you miserable and it can cause problems in your daily life, such as in relationships, at work, or at school. The symptoms of mental illness can be managed with a combination of medications and talk therapy (also known as psychotherapy).
The signs and symptoms of mental illness can vary, which depends on the circumstances, disorder, and other factors. The symptoms of mental illness can affect behaviors, thoughts, and emotions. Here are the most common signs and symptoms of mental illness:
- Suicidal thinking
- Excessive anger, hostility, or violence
- Sex drive changes
- Major changes in eating habits
- Problems with alcohol or drug use
- Trouble understanding and relating to situations and people
- Inability to cope with daily problems or stress
- Detachment from reality (delusions), paranoia, or hallucinations
- Significant tiredness, low energy, or problems sleeping
- Withdrawal from friends and activities
- Extreme mood changes of highs and lows
- Excessive fears or worries, or extreme feelings of guilt
- Confuses thinking or reduced ability to concentrate
- Feeling sad or down
In some cases, symptoms of mental illness can appear as physical problems, such as headaches, back pain, stomach pain, or other unexplained aches and pains. If you have some of the mentioned signs and symptoms of mental illness, then you should see your primary care provider or mental health professional. Most mental illnesses do not improve on their own and if they are left untreated, then they can get worse over time and cause serious problems.
In general, mental illnesses are thought to be caused by a variety of genetic and environmental factors, such as 
Neurotransmitters are naturally happening brain chemicals that carry signals to other parts of the body and brain. When the neural networks involving these chemicals are impaired, then the function of the nerve receptors and nerve system change, and this leads to depression and other emotional disorders. 
It is noticed that mental illness is more common in people whose blood relatives are also having a mental illness. It is known that some genes can increase your risk of developing a mental illness and your life situation can trigger it. 
Environmental Exposure Before Birth
Exposure to environmental stressors, toxins, inflammatory conditions, alcohol, or drugs while in the comb can be sometimes linked to mental illness. 
There are some factors that can increase your risk for mental illness, such as
- A previous mental illness
- A history of mental illness in a blood relative, such as parent or sibling 
- Few friends or few healthy relationships
- Some stressful life situations, such as financial problems, a loved one’s death, or a divorce [4,5]
- A childhood history of abuse or neglect
- An ongoing (chronic) medical condition, such as diabetes 
- Use of alcohol or recreational drugs
- Brain damage as a result of serious injury (traumatic brain injury), such as a violent blow to the head
Mental illness is a very common condition. It is noticed that about one in five adults has a mental illness in any given year. The mental illness can begin at any age, from childhood through later adult years, but most cases begin earlier in life. It is noticed that the effects of mental illness can be temporary or long-lasting. Also, it is possible to have more than one mental illness at the same time. For example, you may have a substance use disorder and depression.
 Mental Health America. The science behind mental illness and recovery. Retrieved from mhanational.org/science
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 Salari N, Hosseinian-Far A, Jajali R, et al. Prevalence of stress, anxiety, depression among the general population during the COVID-19 pandemic: a systematic review and meta-analysis. Globalization and Health. 2020;16.
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