Strong emotions induce the pituitary gland to produce its hormone. This in turn increases breathing, pulse, and heart rate, and may cause a rise in blood pressure. Thus, the pulse of a furious person could reach up to 160 beats/sec, his breathing increases and he gets out of breath. His blood pressure may rise to 21, which makes him at risk of bleeding in the brain, or a clot in the brain or the heart, which means paralysis or sudden blindness.

Scientists say: “Most cases of diabetes are caused by sudden fury.” When man gets furious, his pituitary body induces his suprarenal gland to give orders to the heart to beat faster, to the lungs to breath faster, and to the liver to produce a great amount of sugar, which causes a sudden increase of sugar in the blood. That is why diabetes often comes upon a great sudden anger.
Moreover, fury causes a rise in fat in the blood, which may cause arteriosclerosis, which, in turn, leads to other heart diseases.
Furthermore, fury decreases movement of the intestines. That is why a nervous furious person always suffers of chronic constipation, which causes serious medical problems as ulcers, inflammations or even cancers in the intestines.
However, the most serious danger of fury is that it weakens the immunity system in the human body; and that makes germs more powerful and may cause cancer. That is because the immunity system is responsible for bacterial and cancerous diseases.
The article is long and has many details, but I mentioned the main points. This is fury and that is why forbearance and patience are the best of all human qualities. 

The fruit of monotheism:

Dear brothers, patience is a very high moral value, but monotheism helps you be patient. When you know that everything is under Allah’s Control, that His Actions are all wise, whatever He wills happens, and nothing happens but with Allah’s Will, which is related to the Absolute Wisdom, and His Wisdom is related to the absolute goodness, you no longer feel annoyed. You know that whatever happens is due to Allah’s Will. That is monotheism. It gives peace of mind, relief, tranquility, and trust in Allah.
Suraqa followed the prophet (PBUH) to kill him. The prophet said: “how would you feel if you wore the bracelets of Kisra?” The man was following him to kill him and take a hundred she-camels as a reward, but the prophet (PBUH) was sure that Allah wouldn’t let him down. He was sure that he would arrive Al-Medina, establish a state in it, fight the Persians, and win Kisra’s treasures. He promised Suraqa with Kisra’s bracelets.  He was a true believer, who had trust in Allah’s help and that Allah would never let the believers down. This feeling is healthy.
Listen to these words; Monotheism is healthy. If you want your body systems to work regularly, if you want to have moderate blood pressure, regular pulse and cholesterol be a true believer. Allah the Almighty says:

“Who has created me, and it is He Who guides me; And it is He Who feeds me and gives me to drink. And when I am ill, it is He who cures me; And Who will cause me to die, and then will bring me to life (again); And Who, I hope will forgive me my faults on the Day of Recompense, (the Day of Resurrection),"

[Ash-Shu’araa,, 78-82].

He didn’t say: and Who makes me ill and cures me. Illness is attributed to man, because of his weak faith, he gets furious and has grudge. In other words polytheism is the cause of fury and grudge.
I heard from a man who went to a Western country to have a surgery that a nurse came to his room tidied the flowers and asked him about the doctor who would perform the surgery. He mentioned his name. She answered: No way he has no time. He said: I came from Damascus for him. She said: He has no time. He has performed ten thousand surgeries and none of the them failed. The man felt happy. This nurse came specially to give him high spirit that would make the surgery succeed.
Scientists concluded that the higher the patient’s spirits are the closer he would be to recovery. The believer who has a strong relation with Allah is strong, while the polytheist who is away from Allah has a weak heart.