Almighty Allah never burdens a soul beyond its capacity. Therefore, sickness is a legitimate excuse in the Islamic Shari`ah. When a Muslim falls ill, he or she enjoys concessions and is relieved from certain religious duties.
If a pilgrim who has not assumed ihram and has not started any of its rituals falls sick and becomes obliged to discontinue, he or she will not be subject to any consequential obligation.
Answering this question, the Standing Committee for Islamic Research and Ifta’ stated,
In the case where a pilgrim put off the ihram of `Umrah and then discontinued the performance of Hajj and returned to where he lives before assuming ihram for Hajj, then there is nothing wrong with that. This is because the `Umrah was finished once he performed it and put off the ihram. As for Hajj, he did not even assume ihram for it.