You’re in pain. “A little discomfort during exercise is normal, especially if you’re trying to increase your fitness, but if it persists, is severe or changes the way you’re doing the activity, see a doctor,” says Edward Laskowski, MD. A pain that shoots down your leg, for instance, could mean you’ve injured a disk in your back.
You hear a pop. Acute injuries that require medical treatment, like tears of the anterior cruciate ligament in the knee, may be accompanied by an audible sound.
You can’t put weight on your foot. If your foot, ankle, knee or hip feels weak or wobbly, it’s a sign you’ve done significant damage.
You have swelling. “Swelling of a joint or soft tissue is part of the body’s response to acute damage,” says Laskowski.
You feel headachy and nauseated. These are two signs of hyponatremia, a potentially fatal condition characterized by abnormally low blood sodium that may affect as many as 13 percent of recreational marathon runners. It can occur during long, intense bouts of exercise when you’re sweating a lot and drinking water to hydrate, which dilutes the sodium level in your blood. That’s why doctors recommend electrolyte-enhanced sports drinks if you’re exercising for roughly an hour or longer.
You’re unusually tired. Ongoing fatigue can signal a thyroid problem, a common condition in midlife women. “One of the key signs is that the muscles fatigue easily and the tendons are painful,” says Jo Hannafin, MD. If lots of things start to hurt, ask your doctor to test your thyroid.
Originally published in the October 2010 issue of More.