We ask Allaah to heal you and enable you to be patient and to seek reward with Him so that you may attain the reward in full. Allaah has reduced the burden for the one who is sick and has allowed him not to fast in Ramadaan, so long as he makes up the days when he did not fast after the sickness is over. Allaah, may He be exalted, says (interpretation of the meaning): 

“but if any of you is ill or on a journey, the same number (should be made up) from other days”

[al-Baqarah 2:184]

Ibn Qudaamah al-Maqdisi (may Allaah have mercy on him) said: 

The scholars are unanimously agreed that it is permissible for those who are sick not to fast, and the basic principle concerning that is the verse in which Allaah says (interpretation of the meaning): “but if any of you is ill or on a journey, the same number (should be made up) from other days”. End quote. 

Al-Mughni, 3/88 

The kind of sickness which makes it permissible not to fast is that in which a person will be harmed by fasting, or fasting will delay his recovery. Taking medicine is not an excuse unless it is not possible to take it at any time other than the day of the fast. If the sick person can take the medicine at the time of sahoor and after Maghrib, and fasting does not harm him, then it is not permissible for him not to fast. If he needs to take the medicine during the day, then there is no sin on him if he breaks the fast and makes up the days that he missed.

Al-Nawawi (may Allaah have mercy on him) said:  

Our companions said: The condition that it be permissible not to fast is that fasting will cause him hardship that is too much for him to bear. As for a mild sickness that does not cause any obvious hardship, it is not permissible for him not to fast, and there is no difference of opinion among us. End quote. 

Al-Majmoo’, 6/257 

Ibn Qudaamah (may Allaah have mercy on him) said: 

The kind of sickness which makes it permissible not to fast is sickness which is severe and may get worse in the case of fasting, or where there is the fear that fasting may delay recovery. 

It was said to Ahmad: When can a sick person break the fast?  He said: When he cannot fast. He said: Like a fever? He said: What sickness is worse than fever? End quote. 

Al-Mughni, 3/88 

Shaykh ‘Abd al-‘Azeez ibn Baaz (may Allaah have mercy on him) said: 

What is prescribed for the sick person is not to fast during Ramadaan if fasting will harm him or is too difficult for him, or if he needs treatment during the day in the form of medicine, pills and the like, which are eaten or drunk, because Allaah says, “but if any of you is ill or on a journey, the same number (should be made up) from other days”, and the Prophet (peace and blessings of Allaah be upon him) said: “Allaah likes His concession to be accepted just as He dislikes sins to be committed.” According to another report: “As He likes His commandments to be fulfilled.” End quote.

Fataawa Islaamiyyah, 2/139 

Shaykh Ibn ‘Uthaymeen said: 

If the sick person takes his medicine during Ramadaan after dawn comes, then his fast is not valid, because he has deliberately broken the fast, but he has to refrain from eating and drinking for the rest of the day, unless it is too difficult for him to refrain because of his sickness, in which case he may break the fast because of the sickness, but he has to make it up, because he deliberately broke the fast. 

It is not permissible for a sick person to take medicine when he is fasting in Ramadaan, except in the case of necessity, such as if we fear that he may die, in which case we would give him medicine to help him. In this case he is breaking the fast but there is no sin on him if he breaks his fast because of sickness. End quote. 

Fataawa Ibn ‘Uthaymeen, 19/question no. 76 

If your sickness is ongoing and chronic, and means that you cannot make up the fasts, then you do not have to fast or make up the fasts, rather what you have to do is to feed one poor person one meal for each day in Ramadaan that you do not fast. 

Shaykh Muhammad ibn Saalih al-‘Uthaymeen (may Allaah have mercy on him) was asked: 

There is a sick man who has heart disease; only a small part of his heart works and he needs to take medicine all the time, i.e., approximately every six or eight hours. Is fasting waived in his case? 

He replied: 

Yes, fasting is waived in his case, and he should feed one poor person for each day. If he wants he may give each poor person one-quarter of a saa’ of rice, and if he gives some meat too that will be better, or if he wants, he may offer them dinner on the last night of Ramadaan, or lunch on any day after Ramadaan. Any of these options is permissible. End quote. 

Fataawa Ibn ‘Uthaymeen, 19/question no. 87. 

With regard to various types of sickness, see the answer to question no. 38532. 

And Allaah knows best.