The World Health Organization said on its website that the observance is a chance to "make mental health care a reality for people worldwide."
Mental health issues span a broad spectrum, from anxiety disorders to personality disorders and everything in between.
Stress is also a big issue for millions of people and something that affects everyone, according to the National Institute of Mental Health.
Stress is defined as the body and brain's response to any demand, including work, school, exercise, major life changes and traumatic events, the NIMH said on its website.
"Stress can be positive, keeping us alert, motivated, and ready to avoid danger," officials with the Cleveland Clinic said on their website. "Stress becomes negative when a person faces continuous challenges without relief or relaxation between stressors. As a result, the person becomes overworked, and stress-related tension builds."
Chronic stress can cause long-term health issues, like digestive issues, sleeplessness, anger or irritability, officials with the NIMH said. And routine stress can be the worst of all because it can lead to diseases like heart disease, high blood pressure, diabetes and other illnesses, the NIMH reported.
Tips on reducing stress, according to the Cleveland Clinic, include:
-Maintain a positive attitude.
-Learn and practice relaxation techniques, like meditation or yoga.
-Manage your time.
-Be assertive, but not aggressive.
-Eat right and get enough sleep.
-Make time for hobbies.
If stress becomes unmanageable, seek out professional help.