There are healthy ways to relax like exercise, gardening, reading, listening to music, laughing with friends, watching a movie, taking a nap, playing with an animal, or sitting on the porch and enjoying the quiet. All of those have the potential to renew you after a long day, but there is another very common practice we use to relax that can be dangerous.
Many of us use nicotine or alcohol to relax, and used in moderation, there would probably not be a problem. The issue though is when one drink or cigarette turns into several and continues to grow until you are dependent on what you used to see as a pleasant decompressor. I am not trying to be preachy, but I would love to help someone else avoid what I saw happen to two people I love.
My sister used to have a glass of wine after dinner, but the one glass gradually became a bottle as she was faced with breast cancer, divorce, and the loss of her partner. It happened over a long period of time, and by the time we realized how much she was drinking daily, she was completely dependent, but refused to admit there was a problem.
My mom smoked her whole life, but I think she always thought she could stop whenever she wanted. Having a cigarette now and then turned into chain smoking and she died of emphysema. She used to smoke a cigarette with her oxygen tank on which could have caused an explosion.
If you use substances to relax, be careful that instead of relaxing, you are trying to medicate yourself to avoid the roller coaster ride of life. Addiction can sneak up on you until instead of relaxing, you have another problem to worry about.