Muscle soreness is pain or discomfort in one or more muscles, such as those in the legs, arms, stomach, or back. Muscle soreness is a common condition. You might have sore muscles after an intense workout or if you strained the muscle during an activity such as lifting or gardening. Rest, ice, massage, and over-the-counter pain relievers can often help reduce muscle soreness. See your doctor if your muscle soreness lasts more than a few days, especially if you have a rash, numbness, fever, redness, or swelling. Certain diseases, such as fibromyalgia or the flu, can cause muscle soreness and may require specific treatment. Follow the links below to find WebMD's comprehensive coverage about how muscle soreness develops, from common causes to possible prevention, and much more.