It's normal for people to be jealous. Jealous people exhibit standard traits and behaviours. One of them is to put the person down. They will make statements about that person either behind their back or in front of them to reduce their sense of self-worth. One of the most common statements such a person will say is, "you look tired".
A negative statement brings out the jealousy out in an obvious way. The jealousy cannot stay hidden in the system, it needs to find a way out. So make some statement which will hurt. The jealous person feels as if he has achieved his objective. The person whom he envied has received a bolt. Jealous people keep throwing their insulting comments, it becomes their habit. Jealousy eats your virtue like fire which eats wood. You become characterless.
There may be few genuine cases where the "you look tired" statement may not arise out of jealousy, but out a serious concern. But concern needs to be addressed sensitively. Your genuine concern if not expressed in the right manner may hurt the other person. Also, if the person is really looking a bit tired, so what ? Maybe, he had a late night, or down with a mild illness. By puncturing his ego that he is not looking good is unnecessary. Positive people say positive thing to lift others up. When you meet a 90 year old man, try telling him that today he is looking nice and energetic. Lift others up. Say loving things, be sensitive to feelings, everyone has their inner ego and self-respect, giving it a soothing massage is not wrong, it is a sign of human compassion. Inspiring people inspire others not through their intellectual depth but through their emotional touch and human sensitivity. So the next time you meet an ugly, old, tired looking person, tell him something positive. Make him feel good about himself. When you touch the inner most part of his heart, you will awaken the inner humanity in you. At that point, even the jealous person will be ashamed to openly say "you look tired".