Missing Salah For A Long Time Due To Illness
One should try their best to offer Salah in all circumstances and on time. In the presence of any ‘ undue difficulty ‘, one has option to combine and reduce the prayers and can also pray with signs only, if standing up properly is not possible. And if praying on time is not possible due to ‘ undue difficulty ‘, then one should offer that Salah as soon as one gets out of that undue difficulty , it will not be considered Qaza. If one realizes after so many years of not praying about offering Salah, then one can make the intention of praying missed farz salah when offering Nafil Salah. There’s nothing explicit mentioned in Sharia about this issue (i.e. Qaza-e-Umri ), but this is opinion of Ibn-e-Taimiya and Ghamidi Sahab also prefers this opinion.