1.      If anyone is so ill that fasting will be injurious or there is fear of aggravation or it may prolong then such a person may not keep fast and should offer compensatory fast after recovery. But it is not proper to give up fasting merely. upon one's own guess unless some pious Muslim Hakeem or Doctor advises.

2.  If the Hakeem or Doctor is a non-believer or does not follow the religious code, his advice should not be trusted and fast should not be given up.

3.  If on personal experience some symptoms convince one that fasting will be harmful, then such a person may give up fast. But if one has no personal experience and is not aware of the condition of the illness, then fast should not be given up on own guess. If not on the advice of a pious Hakeem but on ones own experience a fast is given up, then reward shall have to be given and it will be a sin to give up the fast.

4.  A person has recovered from illness but is still weak and it is feared that the illness will revive if he fasts, then it is allowed for him not to keep it.

5.  If anyone is in journey, then it is permissible for him not to keep a fast and keep compensatory fast after returning from the journey. Traveler has already been described. The same rules apply here.

6.  If there is no inconvenience in fasting during a journey. For instance he is travelling by train and hopes to reach home by the evening or has everything of comfort, then it is better to keep a fast in the journey and if no fast is kept then there is no sin. A missed fast should be observed. In case fasting in a journey causes discomfort or inconvenience, then it is better not to keep a fast.

7.  If anyone did not recover from illness but died in it or died while in journey, then for the period that he did not fast in illness or journey, then he will not be held responsible for those on the Day of Judgment as he did not have time to keep the missed fasts.

8.  If anyone missed ten fasts in illness and then was well for five days but did not keep missed fasts in this period, he will be held responsible for these five fasts which he did not keep and the rest fasts will be remitted by Allah. But if he was well for full ten days and did not keep the ten missed fasts, then he will be held responsible for ten days. So it is essential for such a person, if he has the means, to make a will before dying for reward (Fidiyah) to be given for the days he is likely to be held responsible.

9.  The same rule applies to the fasts missed in a journey. A will should be made for reward of the missed fasts.

10. If anyone in a journey stays at a place with the intention of staying for fifteen days, then he should not give up fast as according to Shari’ah now he will not be treated as a traveler. But if the intention is to stay for leas then fifteen days, then it is permissible not to keep fast.

11. A pregnant woman or one with a suckling baby may not fast for the fear of her own-self or of the baby and should keep the missed fast later. But if her husband has the means he may engage a wet-nurse and relieve the wife and then it would not be permissible for the wife to give up fasts. But if the child is of such nature that it will not take milk from anyone else except the mother then it is permissible for her to give up fast.

12. If a wet-nurse took employment for a suckling baby and Ramadan came and the child's life will be at risk if she fasts, then nurse may also not keep fast.

13. If during Ramadan a woman has monthly course or gave birth to a child, then for period of menses and after birth discharge she may not keep fasts.

14. If a woman was relieved of the discharge at night then she should fast next morning. If she did not bathe in the night even then she should keep a fast and bathe in the morning. But if she is relieved in the morning then she should not fast that day but it is not proper for her now to eat or drink but should remain like the fasting ones.

15. If anyone accepts Islam during day or attained maturity in the day then it is not permissible for such person to eat or drink for rest of the day. But he did eat, and then compensatory fast for such person is not essential.

16. Being in journey one had no intention of keeping a fast, but reached home an hour before mid-day or stayed somewhere with an intention of staying for fifteen days and nothing was eaten or drunk up to this time, then should now resolve for a fast.

17. It is not proper to give up the Ramadan fast without any legitimate cause, it is a major sin. It should not be thought, he will keep a postponed fast for each missed fast as it has been described in the Tradition that even if fast is kept one whole year for one missed fast even then it cannot be equal to the reward of one fast of Ramadan.

18. If one has the misfortune of not keeping a fast then he should not eat or drink in presence of others and should neither declare that he is not fasting as publicizing a sin is also a sin and if declared it would be a double sin-one of not keeping a fast, and the other of publicizing it. One who is not keeping a fast due to some reason; he too, should not declare it others.

19. When boys and girls are capable of keeping fast they should be made to keep fast and should be compelled to keep fast when they attain the age of ten years. If fast of one month are not possible for them to keep then as many as possible should be kept by them.

20. If a minor boy or girl breaks a resolved fast then he or she should not be forced to observe a postponed fast but if prayer is disrupted after making intent, then they should be made to repeat it.

Source: www.islamawareness.net