Big pharma stocks have surged behind the market's rally, but that doesn't mean that every company in this top health care industry's performing up to healthy standards. Between the patent cliff and the latest China bribery scandal, several top pharmaceutical companies have endured a tough stretch of setbacks lately that could haunt their stocks in 2014.

GlaxoSmithKline's (NYSE:GSK) been at the center of the China scandal through the second half of 2013, and while the company expects to bounce back in the world's second-largest economy this year, is GlaxoSmithKline on track to recover from a 61% drop in China sales in the third quarter? Meanwhile, both Eli Lilly (NYSE:LLY) and AstraZeneca (NYSE:AZN) suffer from lackluster pipelines and withering losses from patent expirations, with their respective drugs Cymbalta and Nexium poised to experience patent cliff-related drop-offs this year.

Despite these looming dangers, can long-term investors unearth real value out of these seemingly hard-hit companies? In the video below, Motley Fool contributor Dan Carroll tells you how GlaxoSmithKline, AstraZeneca, and Eli Lilly could pan out in 2014-and whether or not these three stocks are worth a look for your portfolio.