Minor leg problems, such as sore muscles, are common. Leg problems commonly occur during sports or recreational activities, work-related tasks, and work or projects around the home. Leg problems also can be caused by injuries. If you think your leg problem is related to an injury, see the topic Leg Injuries.

Leg problems may be minor or serious and may include symptoms such as pain, swelling, cramps, numbness, tingling, weakness, or changes in temperature or color. Symptoms often develop from exercise, everyday wear and tear, or overuse.

Older adults have a higher risk for leg problems because they lose muscle mass as they age. Children may have leg problems for the same reasons as adults or for reasons specific to children. Problems are often caused by overactivity or the rapid growth of bone and muscle that occurs in children.

It may be helpful to know what the bones of the thigh and lower leg look like as well as the muscles and tendons to better understand leg problems. Leg problems that are not related to a specific injury have many causes.

• Problems can occur when you "overdo" an activity, do the same activity repeatedly, or increase your exercise. This may be called an overuse injury even though you did not have an actual injury. Examples of overuse injuries includes bursitis, tendinitis, shin splints, stress fractures, plantar fasciitis, or other muscle strains or tears. Muscle cramps can be caused by activity or dehydration, especially when you exercise in the heat. For more information, see the topic Dehydration.
• Problems that affect the blood vessels (vascular disease) can include peripheral arterial disease, inflammation of a vein (phlebitis), or a blood clot (thrombophlebitis).
  • A blood clot near the surface of the skin may cause only minor problems, while a clot in a deep vein may be more serious. Recent surgery, especially on bones or the pelvic or urinary organs, increases the risk of blood clots, especially in deep leg veins. Prolonged bed rest and inactivity, including sitting or standing in one position for long periods of time, or prolonged immobilization of a limb, such as in a cast or splint, also may increase the risk of blood clots.
  • Problems affecting the arteries (peripheral arterial disease) can cause cramping pain that occurs with predictable amounts of exercise, such as walking a short distance, but improves with rest.
• Other diseases, such as osteoarthritis, rheumatoid arthritis, and lupus, can cause joint pain, stiffness, and swelling. A transient ischemic attack (TIA) or a stroke can cause numbness, tingling, or loss of function in one or both legs.

Some leg problems are seen only in children, such as swelling at the top of the shinbone (Osgood-Schlatter disease) and swelling and pain in the knee joint (juvenile idiopathic arthritis). Growing pains are common among rapidly growing children and teens and are probably caused by differences in growth rates of muscle, bone, and soft tissue. These pains often last for 1 or 2 hours at a time and can wake a child from sleep.

Swollen feet are common after you have been sitting or standing for long periods of time or during hot or humid weather. Sitting or lying down and elevating your legs will often relieve this type of swelling. Conditions that put increased pressure on the belly and pelvis, such as obesity and pregnancy, also can cause swelling in the feet and ankles and varicose veins.

• Varicose veins can affect both men and women and may only cause a problem in one leg. For more information, see the topic Varicose Veins.
• The swelling in the feet and ankles that occurs during pregnancy usually gets worse toward the end of the pregnancy and goes away after delivery. For more information, see the topic Pregnancy-Related Problems.

Many medicines can cause problems in the legs. For example, birth control pills and other hormones can increase your risk of blood clots, while water pills (diuretics), heart medicines, and cholesterol-lowering medicines (statins) can cause muscle cramps.

Some leg problems are only present at night:

• Restless legs syndrome causes an intense, often irresistible urge to move the legs. This can interrupt sleep make you overly tired during the day. You may have a "pins-and-needles," prickling, creeping, crawling, tingling, and sometimes painful feeling in your legs. Moving your legs can provide short-term relief. For more information, see the topic Restless Legs Syndrome.
• Nighttime leg cramps are a sudden tightening (contraction) of the leg muscles in the calf, thigh, or foot. They often occur just as you are falling asleep or waking up. They can be painful and can last from a few seconds to a few minutes. Walking or stretching your leg can sometimes help relieve nighttime leg cramps.

Most minor leg problems will heal on their own, and home treatment may be all that is needed to relieve symptoms and promote healing. But serious leg problems also may occur and require prompt evaluation by a doctor.

Check your symptoms to decide if and when you should see a doctor.