The word(s) "disease" appears 20 time(s) in 19 verse(s) in Quran in Mohsin Khan translation.

(1) In their hearts is a disease (of doubt and hypocrisy) and Allah has increased their disease. A painful torment is theirs because they used to tell lies.

(2) It is not Al-Birr (piety, righteousness, and each and every act of obedience to Allah, etc.) that you turn your faces towards east and (or) west (in prayers); but Al-Birr is (the quality of) the one who believes in Allah, the Last Day, the Angels, the Book, the Prophets and gives his wealth, in spite of love for it, to the kinsfolk, to the orphans, and to Al-Masakin (the poor), and to the wayfarer, and to those who ask, and to set slaves free, performs As-Salat (Iqamat-as-Salat ), and gives the Zakat, and who fulfil their covenant when they make it, and who are patient in extreme poverty and ailment (disease) and at the time of fighting (during the battles). Such are the people of the truth and they are Al-Muttaqun (the pious - See V.2:2).

(3) And you see those in whose hearts there is a disease (of hypocrisy), they hurry to their friendship, saying: "We fear lest some misfortune of a disaster may befall us." Perhaps Allah may bring a victory or a decision according to His Will. Then they will become regretful for what they have been keeping as a secret in themselves.

(4) When the hypocrites and those in whose hearts was a disease (of disbelief) said: "These people (Muslims) are deceived by their religion." But whoever puts his trust in Allah, then surely, Allah is All-Mighty, All-Wise.

(5) But as for those in whose hearts is a disease (of doubt, disbelief and hypocrisy), it will add suspicion and doubt to their suspicion, disbelief and doubt; and they die while they are disbelievers.

(6) See they not that they are put in trial once or twice every year (with different kinds of calamities, disease, famine)? Yet, they turn not in repentance, nor do they learn a lesson (from it).

(7) O mankind! There has come to you a good advice from your Lord (i.e. the Qur'an, enjoining all that is good and forbidding all that is evil), and a healing for that (disease of ignorance, doubt, hypocrisy and differences) which is in your breasts, - a guidance and a mercy (explaining lawful and unlawful things) for the believers.

(8) "And press your (right) hand to your (left) side: it will come forth white (and shining), without any disease as another sign,

(9) That He (Allah) may make what is thrown in by Shaitan (Satan) a trial for those in whose hearts is a disease (of hypocrisy and disbelief) and whose hearts are hardened. And certainly, the Zalimun (polytheists and wrong-doers) are in an opposition far-off (from the truth against Allah's Messenger and the believers).

(10) Is there a disease in their hearts? Or do they doubt or fear lest Allah and His Messenger (صلى الله عليه وسلم) should wrong them in judgement. Nay, it is they themselves who are the Zalimun (polytheists, hypocrites and wrong-doers).