We bring to your attention a wonderful book by the authoritative Muslim scientist Muhammad Salih al-Munajid, dedicated to heart ailments. The topic of the book is very important for any believer, and today it is no less relevant than in the first centuries of the existence of Islam. Both early and late Muslim scholars paid a lot of attention to the heart and the ailments that beset it, leaving us with many valuable works in this area. Familiarity with the ailments that can afflict the heart of a believer helps us to be vigilant and guard against them. In addition to describing these ailments and narrating what contributes to their occurrence, the author of the book offers the reader effective methods of treating them and gives advice on how to protect themselves from them. This work is based on Quranic verses, hadiths of the Prophet and statements of famous Muslim scientists, such as Ibn al-Qayyim, Ibn al-Jawzi, Ibn Rajab and others. The book is addressed to a wide range of readers - not only Muslims, but also everyone interested in moral health.