Who is Not Allowed to Fast in Ramadan

The normal and healthy Muslim should fast from puberty, and the Prophet said:

"Three are exempted from fasting: the mentally ill, until he is healed, the sleeper until he awakens, and the child until puberty"

As for women , Do not fast the days of the menstrual period and after childbirth until blood stops flowing. Then you must compensate for non-fast days.

a) The traveler : Within the characteristics that allow him to shorten the prayers can fast or not. Said Abu Sa'id al-Judri "In our expeditions with the Prophet, some
fasted, others did not, in Ramadan, the fasting did not censure those who did not fast, who had the strength to fast did,
كنا نغزو مع رسول الله عليه وسلم في رمضان فمنا الصائم ومنا المفطر فلا يجد الصائم على المفطر ولا المفطر على الصائم

B) The sick : If he wants, or if the doctor says that fasting is not possible or convenient, the sick person may not fast, according to what God says in the Holy Qur'an:
ولا تلقوا بأيديكم ىلى التهلكة
Do not jump to self-destruction " (ALBAQARA, 195).

After recovering health he should fast the days he did not fast in Ramadan. If the illness that hinders fasting is chronic, it will compensate for your non-fasting by feeding a needy person each day of non-practiced fasting, if he has the means. Of which Allah says:
وعلذ الذين يطيقونه فدية طعام مسكين
"Those who are unable to fast feed a poor".

If he could not compensate him for economic reasons in this way, he is exempt from doing so.
C) The elder : The Muslim, male or female, who arrives in old age at an age when he does not have the strength to fast, is exempt, and must compensate for not fasting by giving some food to those who need it. Ibn Abbas says:

"The old man was allowed to feed a needy man."

D) The pregnant or breastfeeding woman : If the believer is pregnant or breastfeeding, she can compensate for her non-fasting, fasting as many days when her situation allows her and, in addition, she can feed an equal number of days.

E) The distracted : He who forgets that he is fasting and eats or drinks something, realizing his distraction should abstain immediately, and will not lose his fast, according to the hadith of the Prophet, for in that case God gave him to eat or to drink.
من نسي وهو صائم فأكل أو شرب فليتم صومه فإنما أطعمه الله وسقاه
The fasting may in Ramadan, during fasting hours, rinse his mouth and nose with clean water, bathe, clean his teeth without toothpaste, and swallow his saliva. Anyone who sleeps will not commit his fast.