Hypophosphatasia (HPP) is a rare inherited disease with a heterogeneous clinical expression. The adult form of HPP is often difficult to be recognized with a delayed diagnosis and inappropriate treatments. Though severity of HPP decreases with age at onset, important complications could occur at any age and the burden of HPP among adult patients is found to be significant. Adult patients with HPP suffer of chronic pain, recurrent fractures and other orthopedics problems, with severe disability that have a serious negative impact on all aspects of their life. The aim of this paper is to summarize the main aspects of HPP in adult patients reviewing the literature and focusing on its burden for patients suffering from this condition.