Many medical conditions can cause pain in the legs that can also be associated with fatigue. Determining which of these conditions may be causing the dual symptoms requires a thorough understanding of patient history, what brings symptoms on, what improves them and what other symptoms are present. Putting all of this information together requires consultation with a physician, but patients may find it helpful to understand some of the possible causes beforehand.
Over-training
Over-training is a type of over-exertion that can cause both fatigue and muscle aches. It is usually seen in competitive athletes, but according to the June 2003 edition of "The Physician and Sports Medicine," it can occur in ordinary fitness enthusiasts who exercise intensely over an extended period of time. Other symptoms of over-training syndrome include irritability, insomnia, anxiety and increased susceptibility to infection. It is more likely to affect the New Year's resolution-type---that is, someone who drastically increases regular exercise after a long period of inactivity.
Circulatory Causes
Disorders that decrease circulation to the legs can cause aching and fatigue. An example of such a disorder is peripheral arterial disease, or PAD. PAD is caused by atherosclerotic plaques that block arteries in the extremities, similar to the plaques that block coronary arteries in coronary artery disease. PAD classically causes leg pain while walking or climbing stairs, and improves with rest. Frequently there is an overall feeling of fatigue due to decreased circulation. PAD typically affects older individuals with a long history of cigarette smoking and other cardiovascular disease risk factors, such as high cholesterol and diabetes. PAD is a potentially dangerous disorder as it may also indicate a serious degree of coronary artery disease.
Autoimmune Disorders
Autoimmune disorders occur when the immune system mistakenly recognizes part of the body as a foreign invader and attacks it. Autoimmune disorders typically cause pain in the area under immune attack as well as constitutional symptoms, such as fever and fatigue. Polymyalgia rheumatica is an example of an autoimmune disorder that can cause leg muscle aches and fatigue. Other symptoms include fever, malaise and unintended weight loss. Polymyalgia rheumatica typically affects older individuals and is more common in those of northern European ancestry. Like most autoimmune disorders, it affects women more often than men.
Fibromyalgia and Chronic Fatigue Syndrome
Fibromyalgia and chronic fatigue syndrome, or CFS, are diagnoses of exclusion. This means that they are not so much causes of leg pain and fatigue, but are diagnoses given when other causes can not be determined. Fatigue, headache, muscle aches and sleep disturbance are among the symptoms common to both syndromes. Fibromyalgia symptoms are more closely associates with increased pain perception and CFS symptoms more with fatigue and flu-like complaints; given their common features, however, these differences may represent a spectrum of outcomes from a common underlying disorder. Attempts to find specific biochemical, radiological or anatomical features that characterize either disorder have met with, at best, inconsistent results, according to a review article published in the October 2004 issue of the APLAR Journal of Rheumatology. Depression is a common feature of both syndromes, and treating this depression frequently improves the symptoms. This fact does not necessarily imply that the syndromes are fundamentally psychiatric, however, since depression can lead to fatigue and increased pain sensitivity.
References
- "The Physician and Sportsmedicine"; Overtraining Syndrome; Christopher J. Hawley; June 2003
- "Harrison's Principles of Internal Medicine"; Dennis L. Kasper; 2005
- "APLAR Journal of Rheumatology"; Fibromyalgia and Chronic Fatigue Syndrome; Peng Thim Fan; October 2004
