Minor Ache or Major Problem? 6 Symptoms Exercisers Should Pay Attention To

Warning Signs

A few years ago a strange thing happened at the end of a hike. My heart suddenly felt fluttery. Was I having a heart attack? I couldn't be. I was young, healthy, and strong enough to cover three miles of tough terrain. I must have just overdone it, I decided.

But the next morning, my pulse still wasn't right, so I called my doctor. She said to come in at once. Fortunately the EKG showed that it wasn't a heart attack; the problem was a minor thyroid imbalance. I was lucky, but the experience was an eye-opener.

Even if you exercise and are keyed into your body, you can still misread its warning signals. In fact, "young, fit women often tend to ignore them," says Ed Laskowski, MD, codirector of the Mayo Clinic's Sports Medicine Center in Rochester, Minnesota. But some aches and symptoms could be more serious than you think. Here's the heads-up on six scenarios that are likely to trick you.