This paper describes preliminary analysis of health-related social media postings in Twitter. We classified Tweets two ways: those (A) with and (B) without linked URLs, and similarly for users, those commonly posting Category A Tweets and users commonly posting Category B Tweets. The Tweet user groups and the two categories of Tweets show different characteristics in use of user-defined hash-tag terms, the impact of expanded URLs through social media community, and posting period of the two Tweet categories. One user among the top 25 most frequent posters in each user group only posted both Category A and B Tweets. Seven hash-tag terms from the top 25 hash-tag terms obtained from each category were used for both Category A and B. Tweets with and without linked URLs show different characteristics in terms of user groups, hash-tag terms, and the posting period of the linked URLs. © Springer International Publishing Switzerland 2014.