Stress
If you don't want premature wrinkles or gray hair, run! This job isn't for you. Public relations jobs at nearly all levels are loaded with stress.
Deadlines dominate your world. You're dealing with different personalities who want many different things and are highly demanding. Projects that cost a lot of money are under your care and you'd better handle those well. When the client is in trouble, you have to rally quickly to put out lots of fires—again, crazily stressful times.
Many people who love this job say that they "thrive on the stress and excitement." That, and a huge bottle of antacids.