Graphic design is a wonderfully creative field to explore. When the work is coming in and the clients are good, it can be the best job in the world. However, there are several downsides to being a member in this field.
If you freelance, you're on your own - and that means that unless you market yourself and are able to manage clients in a businesslike fashion, your work opportunities will be limited. You will also be responsible for paying your own taxes and insurance, which can be a hefty drain.
While you may have entered the design field because you love to create, a corporate design job often offers little leeway for your own creativity. You will be designing to a client's specifications, not your own - expect to have to make revisions.
Value of Design
Not every company will place the same value on good graphic design; that's why there are so many poor designs in even the highest levels of advertising. The problem is that companies will pay relating to that value and you can easily undersell yourself by doing far too much work for far too little pay.
Everyone's a Designer
With a fresh influx of new graphic design interns becoming full-fledged designers every graduation season, it is easy to have your prices undercut in the freelance and corporate markets. Businesses will often opt to create their own designs as a money-saving tactic rather than hire a professional.
The Shrinking Market
Many problems relating to freelancing are eliminated by taking a permanent position at a design studio, who do the marketing and client negotiations for you. However, these jobs are hotly competed for, so they fill very quickly.