Thanks for your message. I’m sorry to hear about your calf pain. There are a couple of different injuries that affect the calf muscles of runners. I can’t be sure which one is affecting you, but I hope that by describing both of them I will give you the information you need to zero in on a diagnosis and course of treatment with your doctor.
Calf Strain: A calf strain is a mild or moderate tear in either of the two major muscles on the back of the lower leg: the gastrocnemius or the soleus. It is usually characterized by pain in the belly of the muscle or close to the Achilles tendon attachment. The onset is typically fairly sudden. For example, you may experience pain the day after completing an unusually hard or hilly run, or feel a sudden twinge during a speed workout. When a calf strain makes running painful you must stop running and cross-train (for example on an elliptical trainer) until you can run pain-free once more, then ease back into it. To prevent the recurrence of a calf strain, stretch your calves and Achilles tendons regularly, strengthen your lower legs by balancing one-legged on a pillow, and avoid sudden increases in fast running and hill running. Regular sports massage or ART may also help you avoid future calf muscle strains by keeping the tissue more supple.
Compartment syndrome: Compartment syndrome occurs when running causes one or more of the muscles of the lower leg to grow faster than the sheath containing the muscle, causing pressure to build up inside it. It is generally characterized by non-localized pain that emerges after several minutes of running. Compartment syndrome most often occurs in the anterior and lateral muscle compartments–that is, at the front or outer side of the lower leg–but it can occur in the soleus and gastrocnemius as well. Sometimes compartment syndrome can be resolved with a short break from running, followed by a gradual return. Often, however, surgery is required to relieve the built-up pressure.
Only your orthopedist or sports medicine specialist can definitively diagnose your injury, and I encourage you to see him or her. In the meantime, I hope this information gives you a good sense of the possibilities.