There are other situations that one needs to wash their hands, aside from getting up in the morning. Some are in order to remove ruach hatumah and some because of cleanliness, and by many of them it is a dispute among the Poskim. There are some differences in halacha between the two reasons as well. 1) If it is because of ruach hatumah, then one should try to wash their hands as soon as possible. 2)If it is because of ruach hatumah one needs to wash their hand until the wrist, but if because of cleanliness then just the part of the hand that became unclean. 3)For ruach hatumah one needs water lechatchila.

For example, הקם מן המיטה – one who gets out of bed. Read literally, it seems that every time one gets out of bed even if one did not sleep, one needs to wash their hands. However, the Mishna Berurah says that only if one also slept do they have to wash. We see from here that he holds that the reason is because of ruach hatumah.