Imam Al Uthaymeen said:

“Similarly from going to extremes in worship is that a person makes prayer, fasting or other than it of which Allah has made easy upon him hard upon himself. If he makes that which Allah has made easy upon him hard upon himself, then he is/will be one who is destroyed. From that is that which some of those who are sick do, especially in the month of Ramadan wherein Allah has permitted for him to break his fast since he is sick and in need of food and drink. However he makes it hard on himself and remains fasting, this one as well we say the hadeeth

‘The extreme ones are destroyed’

is applied upon him.” End translation. [Sharh Riyadus Saliheen 2/219]

Translated by

Majid Jawed Al-Afghanee
Abu Layl