The Fasting of Ramadan is compulsory upon every Muslim, male or female, who has these qualifications:
To be mentally and physically fit, which means to be sane and able.
To be of full age, the age of puberty and discretion, which is normally about fourteen. Children under this age should be encouraged to start this good practice on easy levels, so when they reach the age of puberty they will be mentally and physically prepared to observe the Fasting.
To be present at your permanent settlement, your home town, your farm, your business premises, etc. This means not be traveling on a journey of about fifty miles or more.
To be fairly certain that the Fasting is unlikely to cause you any harm, physical or mental, other than the normal reactions to hunger, thirst, etc.
Children under the age of puberty and discretion.
The insane people who are unaccountable for their deeds. People of these two categories are exempted from the duty of fast, and no compensation or any other substitute is enjoined on them.
Men and women who are too old and feeble to undertake the obligation of fast and bear its hardships. Such people are exempted from this duty, but they must offer, at least, one needy poor Muslim an average full meal or its value per person per day. This compensation indicates that whenever they can fast even for one day of the month, they should do so, and compensate for the rest. Otherwise they are accountable for their negligence
Sick people whose health is likely to be severely affected by the observance of fast. They may postpone the fast, as long as they are sick, to a later date and make up for it, a day for a day. As for those whose sickness does not allow them to fast, they fall into three categories:
If it is neither hard nor harmful for them, they must observe fasting.
If it is hard but not harmful for them, they are permitted to break their fast.
If it is harmful for them, then they must abstain from fasting. It is stated in the Qur’an; “Do not kill yourselves and “Do not throw yourselves into destruction. The prophet (peace be upon him) was reported to have said: “Cause no harm to yourselves nor cause it to others”.
People in the course of travelling of distance about fifty miles or more. In this case such people may break the fast temporarily during their travel only and make up for it in later days, a day for day. But it is better for them, the Qur’an tells, to keep to fast if they can without causing extraordinary hardships.
Expectant women and women nursing their children may also break the fast, if its obervance is likely to endanger their own health or that of their infants. But they must make up for the fast at a delayed time, a day for a day.
Women in the period of menstruation (of a maximum of ten days) or of confinement (of maximum of forty days). These are not allowed to fast even if they can and want to. They must postpone the fast till recovery and then make up for it, a day for a day.
It is also recommended for those engaging in combat in the way of Allah to break their fast. The Prophet (peace be upon him) told his companions in one of the battles: “You are going to meet your enemy in the morning, abstaining from fasting is better for your strength, so break your fast”.