Hi Annelie, and welcome to the forum. Could you post a picture or two of the plant? Some leaf loss is going to occur. Usually the oldest ones at the base will get used up by the plant, shrivel and yellow. Leaf loss throughout indicates a more serious situation. Most new growers (speaking from my own horrid experience) overwater their first orchids. The roots drown, and the leaves follow their demise because roots are not sending water to the leaves. Phal roots need air and they must be allowed to become nearly dry. Orchids purchased at a grocery store are often potted in sphagnum moss. The moss stays way too wet for too long and the roots rot. Does this sound like the situation? Joe