Leg aches can be caused by a number of different conditions ranging from the simple to the very serious. The simplest of leg aches are caused by tired, overused, or under-conditioned leg muscles after physical activity. Muscle strains are slightly more serious, and they require ample rest to heal. More serious conditions that can cause leg aches include varicose veins, arthritis, traumatic injury, or nerve damage. These conditions will most likely require medical attention, though some of them can heal with simple exercise and stretching. In the case of a traumatic injury — such as a bone break or muscle tear — surgery may be necessary.
Not using the legs for long periods of time can also cause leg aches. A lack of blood flow delivering oxygen to the muscles can cause a sensation of weakness, tenderness, or achiness. Sitting or standing for long periods of time can also cause leg aches; as the muscles tire from holding the body in position, they tend to tighten. Tight muscles can lead to muscle strains, which can in turn cause pain or aches anywhere in the legs. These are generally minor issues that can be solved by stretching and regular exercise, as well as by practicing proper posture.
Sciatic nerve pain can also cause leg aches. The sciatic nerve is a long nerve that runs from the bottoms of the leg up into the lower back. When the nerve or any of its endings gets compressed, shooting or sharp pains can be felt all the way down the leg, in the buttocks, or in the lower back. In most cases, appropriate stretching and exercise can relieve sciatic nerve pain, though in other instances, physical therapy, medication, and even surgery may be necessary. Sciatic nerve pain can be caused by a herniated disc in the spine, which is a more serious condition that will require more consistent rehabilitation and even possibly surgery.
Arthritis occurs when the tissue within joints begins to atrophy or disappear altogether, causing inflammation and rubbing among the bones of the joint. Bone spurs can develop as a result, and leg aches are likely. Arthritis becomes more common as the body ages, and while some cases of arthritis cannot be completely cured, anti-inflammatory medication and regular exercise can help alleviate some of the pain. Traumatic injuries such as bone breaks and severe muscle tears can cause severe leg aches and will require medical attention immediately after the injury occurs.