Stress could have a variety of effects on our lives. Although not all kind of stresses {can use the word "stressors") are harmful, the stress of the modern life is often harmful. {stress from modern life}You have to worry about everything because everything is changing rapidly. The question is, how we can reduce our stress? People do different things to avoid stress like watching TV, drinking coffee, tea, or alcoholic things and so on. I think one of the best ways of reducing stress {"of" is not incorrect, but could use "to reduce stress" to sound a bit more natural} is, going over the reasons, which has made the stress. {"the reasons, which has made the stress" --> the sources of stress OR stressors}

Many times we have stress because of an unreal reason. We just need to think about things more clearly to remove the reasons of the stress. For instance, when I was in university one of my friends was always under a lot of stresses. {"a lot of stress", if you use the word a lot, it usually implies plural} He was scared of the future{ can use ; here} of the things that could happen in the future. I remember that once he couldn't sleep for all night. {don't need to use "for" if you use "all night"} In the next morning {can just say "The next morning when I saw him"} I saw him, while {can take out "while"} he was sleepy and was not able to focus on the class. I knew it was because of the {can take out "the"} last night. When I saw that his stress was affecting him badly, I decided to help him. However, I did not know how I should have done it. When he came back to the dormitory, I asked him about things that did not let him sleep last night. He said that he was worried about the results of the exams. I couldn't believe {it OR him} because he had taken his last exam several days before. I said to him that he couldn't do anything for it {about it}, because the exam days were over . He said that he knew but he couldn't stop thinking about them. Finally, I told him If {no capital "I"} he wanted, he could be worried and ruined his next classes. It seemed that he was convinced to focus on his next classes instead of being worried about something hat he was not able to do anything for it. This experience taught me that many reasons of the stresses we have could be unreal. {could use "imaginary" instead of "unreal"}

What is the best way of reducing the stress of modern life ?

Stress has a variety of effects on our lives. Although not all kinds of stress are harmful, the stress of modern life is often harmful. You have to worry about everything because everything is changing rapidly. The question is: how we can reduce our stress? People do different things to avoid stress like watching TV, drinking coffee, tea, or alcohol and so on. I think one of the best ways of reducing stress is to analyze the cause of the stress.

Many times we have stress because for imaginary reasons. We just need to think about things more clearly to remove the reasons of the stress. For instance, when I was in university one of my friends was always under a lot of stress. He was scared of what his future might hold. I remember that once he couldn't sleep all night. The next morning I saw him, he was sleepy and was not able to focus on the class. I knew it was because of his sleepless night. When I saw that his stress was affecting him badly, I decided to help him, but I didn't know how.  When he came back to the dormitory, I asked him about things that prevented him from sleeping last night. He said that he was worried about the exam results. I couldn't believe it, he had taken his last exam several days before. I said to him that he couldn't do anything about it, because the exam is over. He said that he knew but he couldn't stop thinking about them. Finally, I told him if he wanted, he could be worried and ruin his grades in his current classes. It seemed like I was able to convince him to focus on his current classes instead of being worried about something that he couldn't do anything about. This experience taught me that stress can be something made in our minds, not by the world around us.