The obligation of Kibbud Ab Va’em (respecting parents) applies even if fulfilling one’s parents’ needs entails a great deal of difficulty. "Sa’ar" – distress – exempts one from the obligation to reside in a Sukka on Sukkot, but not from the obligation to respect one’s parents. Therefore, if, for example, one has aged parents who require constant care, and caring for them entails immense effort and hardship, one is nevertheless obligated to provide the care they need, even if this includes difficult and time-consuming jobs. However, one is allowed to find somebody else to perform these tasks on his behalf in order to alleviate the burden of caring for the parents.
One is not required to provide care for his parents if this would cause him to become ill. Although one must endure hardship for the sake of respecting his parents, the Misva to respect parents does not require performing tasks that would be detrimental to one’s health. If such a task is needed, one should try to find somebody else to perform the given the task.
All this applies to caring for the parents’ needs – such as feeding them, bathing them, dressing them, and other tasks which benefit the parents. If a parent asks the child to do something that does not directly benefit the parent, then he does not have to obey the wish if the request entails a considerable hardship and difficulty.
Summary: One must care for his parents’ needs even if this entails a great deal of hardship, though one may find somebody else to perform the needed tasks in order to alleviate the burden. One is not required to perform tasks for his parents that would be harmful to his health, and he should find somebody else to perform such tasks.