They may look sexy and slip in just right under your slinkiest evening dresses, but brassieres with thin straps could cause headaches and lead to serious nerve damage.

Physicians at UT Southwestern Medical Center at Dallas say wearing thin bra straps too tightly is dangerous for women. If a strap is so tight that it digs into the shoulder, it puts downward pressure on the cervical nerve. The cervical nerve runs from the neck to the shoulder and is an important component of the nerve system. Damaging it can cause frequent headaches, neck pain or numbness. Over time, it can cause pain that radiates from the shoulder all the way down the arms and into the hands.

Tight bra straps are especially hazardous for full-busted women, but all women are susceptible. Swimsuits with spaghetti straps and shoulder-strap purses worn for several hours at a time are other culprits.

The solution is to find a good-fitting undergarment, say UT Southwestern physicians. Shop for support bras with wide straps. This distributes the weight more evenly.

So the next time you get a headache -- check your bra.