The disease of hasad is very dangerous for one's religion and feelings of brotherhood. If a person has such a disease, he should do what he can to remove it. Taataay has suggested the following steps to help remove hasad from one's heart: (1) The person should remind himself of the evil effects of hasad, both with respect to this life and the Hereafter. When he sees how it hurts his friendship and interaction with others - how he cannot even approach them with a clean heart - he should realise that he is the person who is losing. When he thinks about how displeasing this quality is to Allaah سبحانه و تعالى, this should also move him to try to purify himself from this disease. (2) If the feeling of hasad comes to him, he should do whatever he can to repel it, whether that implies reading the Qur'aan, performing a prayer and so forth.
With respect to that feeling of hasad, people can be divided into the following categories: (1) There are some people who actively work to remove that bounty from the other person, without necessarily destroying the bounty itself. By their speech and their actions they will wrongly do whatever they can to bring an end to the other person's blessing from Allaah. (2) There are others who do not just seek to remove that bounty from the other person, but they also work to get the bounty for themselves.
According to Shaykh Ibn 'Uthaymeen رحمه الله, one of the strong signs that a person is inflicted with the disease of hasad is that he always tries to conceal the virtues and goodness of others. He does not like it when others talk about the good that a person has done. He remains silent and pretends like he does not know of the good that the other one has done.  A true believer who is free of hasad likes it when good things are said about others and when the good deeds of others are appreciated and spoken about. He, himself, when he speaks about others always speaks about their good aspects and the wonderful bounties that Allaah سبحانه و تعالى has bestowed on them. He has no envy in his heart for what Allaah سبحانه و تعالى has bestowed upon the others and, therefore, he spreads that good news to others.  This sign that Shaykh Ibn 'Uthaymeen رحمه الله has explicitly mentioned should be considered a type of subtle sign that people may not notice in themselves. They must take note of this sign and repel it as quickly as possible as it is a stepping stone to the greater forms of hasad. 
This disease of the heart and the sin which is known as hasad was one of the first sins ever committed. It was one of the main things that drove Shaytaan away from his Lord. In fact, two aspects drove Shaytaan to the horrendous situation that he is in today: pride and envy. Shayaan was jealous and envious of Adam عليه الصلاة و السلام because of all of the special blessings that Allaah سبحانه و تعالى gave Adam عليه الصلاة و السلام, including the fact that the angels were ordered to prostrate to Adam عليه الصلاة و السلام and the fact that Adam عليه الصلاة و السلام was given knowledge that Shaytaan was not given. Shaytaan’s response was the classic response of envy and arrogance. He felt that he was better than Adam عليه الصلاة و السلام and did not feel that Allaah سبحانه و تعالى was right in giving such bounties to Adam عليه الصلاة و السلام. The following Qur’anic verse describes part of the situation:
The word translated here as "envy" is al-hasad (الحسد). Ibn Rajab رحمه الله states that hasad is something that is firmly embedded in the nature of man. It is where a person hates to see anyone else being superior or better off than him.  That is all that Ibn Rajab رحمه الله states as a definition of hasad. His definition is definitely not sufficient. The meaning of hasad is more general that what Ibn Rajab رحمه الله stated. Ibn al-Qayyim رحمه الله and al-Qaasimi, in his abridgement of al-Ghazzaali's Ihyaa 'Uloom ud-Deen, have defined hasad as disliking a bounty that another has received and wishing that the other person would lose that bounty. 
First, the believer should dislike the wrongdoer for the dhulm he is committing. He should dislike him because Allaah سبحانه و تعالى dislikes him. Allaah سبحانه و تعالى says,
In the Qur'aan, Allaah سبحانه و تعالى has described mankind as apt to committing a great deal of dhulm to itself and others. For example, Allaah سبحانه و تعالى has said, "If you count the blessings of Allaah, never will you be able to count them. Verily, man is indeed an extreme wrongdoer, an extreme ingrate." (Soorah Ibraaheem, 14:34)
On the authority of Sayyiduna Abu Dharr al-Ghifaari رضي الله عنه, from the Messenger of Allaah صلى الله عليه وسلم, from among the sayings he relates from his Lord سبحانه و تعالى, that He said, "O my servants, I have forbidden wrongdoing for myself and I have made it forbidden for you. Therefore, do not wrong one another."  This qudsi hadeeth is just one of many texts that demonstrate the importance of avoiding any form of dhulm and, hence, being characterised by its opposite of adl or justice.  Allaah سبحانه و تعالى also says in the Qur'aan,