Americans spend billions of dollars each year to relieve their aches and pains.

But a new study indicates some of us are hurting more than others. The research from Princeton University finds that at any given time 28% of Americans are in some kind of pain.

And those who are suffering the most have lower levels of education and lower incomes.

The average pain rating was twice as high for those in households with annual incomes below $30,000, compared with those who make over $100,000 a year.

Researchers say they're also less likely to work or socialize with others.

In other medical news…

Could the quest for shiny lips be hazardous to your health? It's possible.

Baylor university dermatologists say shiny lip balms and glosses could actually attract UV rays, increasing your risk of skin cancer.

They say women should only wear shiny lipsticks in the sun if they wear a lip block with an SPF of 30 underneath.

Signs of lip cancer include a change in the color of the lip surface or peeling and flaking of a spot on the lip.