On one occasion Hazrat Moulana Ashraf Ali Thanwi (rahmatullahi ‘alaih) mentioned:

Apart from the abundant virtues that have been reported regarding sickness, the hadeeth mentions the immense rewards for the sick. It is well-known that when a person exercises patience, he is rewarded. However some researchers (Muhaqqiqeen) opine that in sickness a person receives a separate reward for sickness and a separate reward for being patient. Since sickness is not in one’s volition, instead it comes from the side of Allah Ta’ala, and patience is in one’s volition, therefore both are two separate things and a person will be rewarded for both separately. I always say that in principle, even though a person does not exercise patience when he is ill, he will still receive the reward for sickness. However, he will also be taken to account for not fulfilling the command of Allah Ta’ala with regard to exercising patience. In the month of Ramadhaan many people fast, yet they do not perform their salaah. They will be rewarded for fasting, though they will be taken to account for not performing salaah. (Malfoozaat Hakeemul Ummat 10/ 215)