Usually, you know immediately if you have a broken bone. You may hear a snap or cracking sound, or the bone may even protrude from the skin. But some broken bones are not so obvious.

Stress fractures, which are small cracks in bone, may not immediately appear on X-ray. Instead, they may cause pain, tenderness and mild swelling and can resemble a muscle sprain or strain. 

Sprains are stretches or tears of ligaments, the fibrous bands of tissue that join the ends of bones together. They are caused by direct or indirect trauma that knocks a joint out of position. 

Strains are twists, pulls, or tears of muscles or tendons (tendons attach muscles to bones). Direct blows to the body or excessive muscle contraction also cause them, or they can result from overuse of muscles and tendons.

Stress fractures cause pain and swelling. Sprains cause pain, bruising, and inflammation. As with a broken bone, pain can be severe when ligaments tear completely. Strains also produce pain, muscle spasm, muscle weakness, swelling, inflammation and cramping.

"The key element in making the diagnosis of a stress fracture as opposed to a sprain or strain is the history," states Dr. Jerry Kripal, Emergency Department physician for The Fort Hamilton Hospital. "With a stress fracture the symptoms are not usually related to a specific accident, but are most often related to starting a new exercise, increasing the volume of exercise or adding hills to a previous exercise regimen. Often the symptoms are only noticed when the patient is doing the particular exercise that resulted in the injury."

Treatment for stress fractures usually requires decreasing or stopping training until the pain is gone and an exam reveals that the fracture has healed. A splint or brace may be used. If the fracture doesn’t fully heal in a reasonable amount of time -- which varies depending on the location of the injury -- surgery may be necessary. Recovery typically takes between four to six weeks for the bones of the forefoot.

Dr. Kripal recommends the RICE approach for treatment of sprains. RICE stands for rest, ice, compression and elevation. Rest and use ice to help reduce the swelling. Putting heat on a swollen tissue can make the swelling worse. After 48 hours of rest, start moving the sprained limb. It may be necessary to use some kind of compression device like a brace or tape to support the injured area while you move it gently. Finally, keep the limb elevated while you're resting to cut down on swelling and speed up recovery.

"If the sprain has gone untreated for more than a couple of weeks you should also see a doctor to develop a treatment program for a potentially chronic injury," says Dr. Kripal.

Strain treatment consists of applying cold compresses immediately and repeatedly for 15 minutes every three to four hours for the first day to help reduce swelling. One should then rest the pulled muscle for at least one day and raise the pulled arm or leg muscle above the level of the heart, especially while sleeping.

Since it is hard to distinguish these conditions, it is important to seek medical care for them right away. Only a physician can properly diagnose the condition and ensure you get appropriate treatment.

If you suspect you may have a stress fracture, sprain or strain, discuss the problem with your physician. For a listing of primary care physicians or to find an orthopedist, visit Find A Physician.

Sources:  American Academy of Orthopedic Surgeons; The Merck Manual of Medical Information, Home Edition, 1997.

The Health Alliance provides emergency departments throughout the Tristate at its hospitals:  The Christ Hospital, The University Hospital, The St. Luke Hospitals (East and West), The Jewish Hospital and The Fort Hamilton Hospital.