Scientifically, stress is the body’s reaction or response when changes occur. These responses can be physical, mental, or emotional.
Stress isn’t always negative. It can also be a good thing; keeping us alert and motivated. It usually goes for a short period of time, and your body's usual reactions to them are normal, such as having sweaty palms or feeling butterflies in the stomach. It only becomes negative once we face difficult challenges continuously, without any break or relaxation to keep our minds calm. Due to this, we become overworked, and stress-related tension builds up.
If this continues, it can lead to a condition called distress - a negative stress reaction that can disturb the body’s internal balance, leading to different physical and emotional problems.
Stress also can be harmful in terms of relieving it, such as excessive use of bad behaviour or substances. Some examples of these include alcohol, drugs, self-harm, etc. In reality, these ‘solutions’ don’t actually return the body in a relaxed state; rather, they keep it more stressed, causing more problems.