F­or the most part you know what to expect when you exercise: Your heart beats faster, breathing increases and, if you’re at it long enough, you sweat. Sometimes, however, your body does something out of the ordinary. You start feeling dizzy. You get heartburn.

F­or the most part you know what to expect when you exercise: Your heart beats faster, breathing increases and, if you’re at it long enough, you sweat.

Sometimes, however, your body does something out of the ordinary. You start feeling dizzy. You get heartburn.

How do you know when it’s time to schedule a doctor’s appointment? Here’s what experts say about the most common exercise-related issues.
 
Dizziness
Muscles need more blood when you’re exercising, says Dr. Caroline Abruzese, founding physician and CEO at Personalized Healthcare, LLC, Georgia. “So when you stand up, less blood is going to the brain and causes dizziness.” Dehydration or a drop in blood pressure may also be to blame for post-workout dizziness.

What to do Stop working out. Do not try to work through the dizziness. If dizziness occurs when you stand, lie down with your legs elevated, says Abruzese. Drink water. See a doctor if you continue to experience dizziness.

Body itches and hives
A rise in body temperature during exercise can cause some people to develop hives, says Dr. Debra Jaliman, a New York based board-certified dermatologist. Changes in air temperature and wearing non-breathable fabrics may also trigger allergic reactions.

What to do Shower immediately after your workout to avoid itching caused by toxins sitting on your skin. Your doctor may prescribe antihistamines and topical steroids if hives become a regular problem.
 
Heartburn
Eating or drinking immediately before exercising can cause heartburn or GERD. Drinking big glasses of water before working out can trigger reflux, where stomach acids back up into the esophagus, causing heartburn.

What you can do See a doctor immediately if the heartburn is accompanied by chest pain and/or shortness of breath, signs you may be having a heart attack. Otherwise, try preventing heartburn by taking small sips of water and waiting an hour or two after eating before exercising. See a doctor if your heartburn doesn’t go away.
 
Muscle soreness
Delayed onset muscle soreness most often occurs 24 to 48 hours after a workout. Most DOMS is a micro-injury to the muscle, says Robert Gillanders, American Physical Therapy Association member and spokesman. “It’s structural damage to the muscle itself.”

What to do Starting out slowly may help prevent DOMS in the first place. If you experience soreness, try low-intensity aerobic exercises like swimming or going for a walk, says Gillanders. If you’re really achy, take a day or two off.
 
Side stitch
This common, sharp pain under the diaphragm may be from eating too close to your workout or from breathing improperly. A side stitch is a spasm from the diaphragm related to intensity, says Gillanders. “The higher the intensity, the greater the mismatch of the oxygen demand to the muscle, resulting in a stitch.”

What to do Decrease the intensity, take longer breaths and exhale through pursed lips to elongate the exhalation, recommends Gillanders. Plus, practice good posture, which also helps the diaphragm work more efficiently.