In addition to injuries and muscle cramps, various medical conditions can cause leg pain. This article covers some of the medical conditions that can cause leg pain. Medical conditions involving the cardiovascular system will be discussed in a separate article in this series about leg pain.
Peripheral neuropathy is not a disease in itself, but a symptom of nerve damage in the limbs that is caused by other medical conditions. Peripheral neuropathy is common in patients with diabetes, HIV/AIDS, vitamin B12 deficiency, cancer, lupus, syphilis, lyme disease, rheumatoid arthritis, sarcoidosis, hypothyroidism, toxic exposure, certain genetic diseases and so on. Peripheral neuropathy is a common symptom and it can be inherited, caused by an infection, caused by exposure to certain chemicals, experienced as a side effect of some medications, caused by metabolic disorders or nutritional deficiencies, caused by inflammatory diseases, caused by oxygen starvation or caused by trauma to a peripheral nerve.
Peripheral neuropathy commonly affects the feet and legs. If a nerve that carries sensation from the body to the central nervous system is damaged, a person may experience pain, burning, numbness or tingling in the leg or foot. Proprioception, or the ability to sense where a body part is without looking, can also be affected and a person can become more uncoordinated. If a motor nerve that supplies a muscle is damaged, a muscle becomes weak because it can not contract as well. It is possible for some muscles to become paralyzed, depending on the extent of the nerve damage. In some cases, muscles may cramp up instead of becoming flaccid and weak. Treatment of peripheral neuropathy involves treating the underlying cause of the problem, along with symptomatic care for pain and physical or occupational therapy if necessary.
Another possible medical cause of leg pain is a bone infection, called osteomyelitis. Osteomyelitis is a bacterial infection that can be caused by several different types of bacteria. People can contract a bone infection via a wound, such as when an open fracture occurs or when a person has surgery, or an infection can spread to the bone from a different part of the body. A type of skin infection called cellulitis can spread to underlying tissues and bones in the leg, or an internal infection like a bladder infection can spread to other parts of the body through the bloodstream.
Any patient with a suppressed immune system due to aggressive immunosuppressive therapy or an immune deficiency like HIV/AIDS is more likely to develop infections, including osteomyelitis. Treatment for osteomyelitis includes antibiotic medications to get rid of the infection and medications to control pain. If the infection is not treated early, it is possible for the infection to spread to other tissues in the leg, making amputation of the leg necessary. It is also possible for a person with an untreated infection to go into septic shock when the bacteria infect the bloodstream.
If your leg pain is in your joints, you may have arthritis, or joint inflammation. There are many different types of arthritis, including osteoarthritis, gout and rheumatoid arthritis. More information about the various types of arthritis can be found at http://pain.com/library/2011/05/01-arthritis-awareness-month/. Infections in the joint capsule itself can also cause joint pain. Osteoarthritis, the most common type of arthritis, is caused by “wear and tear” on the cartilage of the joint. Rheumatoid arthritis is an autoimmune disease. Gout is caused by having too much of a substance called uric acid in your body, which builds up in the joints and causes pain and inflammation. Common symptoms of many different types of arthritis include joint pain, joint stiffness or decreased joint mobility and joint swelling. Treatment for arthritis varies depending on the type of arthritis. Talk to your doctor if you think you may have arthritis pain.
Fibromyalgia is a medical condition that can cause muscle pain in the legs and in other parts of the body. In addition to muscle pain, people with fibromyalgia may also have chronic fatigue, sleep disorders, tension headaches and mood disorders. The cause of fibromyalgia is unknown, but researchers think that people with fibromyalgia have a lowered tolerance to pain because of abnormalities in the way that their brains process pain signals. Treatment for fibromyalgia is symptomatic and aims to control pain, improve sleep and treat mood disorders. Not all aspects of fibromyalgia can be treated medically; for example, the frustration that a patient with fibromyalgia may feel in not knowing how to deal with chronic pain and fatigue may benefit from counseling.
Peripheral neuropathy, infections, arthritis and fibromyalgia are just a sampling of the medical conditions that may cause leg pain. These conditions are not as common as muscle cramps and injuries, but a good proportion of older people develop some degree of osteoarthritis and peripheral neuropathy can be caused by a variety of medical conditions. Always talk to your doctor if you have persistent leg pain and you do not know what is causing it.