Through personal health record applications (PHR), consumers are gaining access to their electronic health records (EHR). A new challenge is to make the content of these records comprehensible to consumers. To address this challenge, we analyzed the text unit length, syntactic and semantic characteristics of three sets of health texts: clinical reports from EHR, known difficult materials and easy-to-read materials. Our findings suggest that EHR texts are more different from easy texts and more similar to difficult texts in terms of syntactic and semantic characteristics, and EHR texts are more similar to easy texts and different from difficult texts in regard to text unit length features. Since commonly used readability formulas focus more on text unit length characteristics, this study points to the need to tackle syntactic and semantic issues in the effort to measure and improve PHR readability.