Pain may affect all or part of a leg or arm. Most disorders that cause limb pain affect the legs more commonly. Pain in the joints Joint Pain: Many Joints Pain that seems to be coming from joints can sometimes be coming from structures outside the joints, such as ligaments, tendons, or muscles (see Introduction to the Biology of the Musculoskeletal... read more is discussed elsewhere.
Limb pain may be constant or occur irregularly. Pain may be precipitated by motion or have no relation to movement. Other symptoms, such as warmth, redness, numbness, or tingling, may also be present, depending on the cause of the limb pain.
Causes of Limb Pain
Injuries and overuse are the most common causes of pain in a limb, but people usually know when these events are the cause of their pain. This discussion covers limb pain unrelated to injury or strain. There are many causes.
The most common causes are the following:
Uncommon but serious causes that require immediate evaluation and treatment include
Sudden blockage of an artery in the limb (acute arterial occlusion Occlusive Peripheral Arterial Disease Occlusive peripheral arterial disease is blockage or narrowing of an artery in the legs (or rarely the arms), usually due to atherosclerosis and resulting in decreased blood flow. Symptoms depend... read more )
Deep soft-tissue infection
Heart attack Acute Coronary Syndromes (Heart Attack; Myocardial Infarction; Unstable Angina) Acute coronary syndromes result from a sudden blockage in a coronary artery. This blockage causes unstable angina or a heart attack (myocardial infarction), depending on the location and amount... read more (arm pain only)
Other less common causes include bone tumors, bone infections ( osteomyelitis Osteomyelitis Osteomyelitis is a bone infection usually caused by bacteria, mycobacteria, or fungi. Bacteria, mycobacteria, or fungi can infect bones by spreading through the bloodstream or, more often, by... read more ), and nerve problems such as pressure on nerves or degeneration of nerves (such as caused by diabetes Diabetes Mellitus (DM) Diabetes mellitus is a disorder in which the body does not produce enough or respond normally to insulin, causing blood sugar (glucose) levels to be abnormally high. Urination and thirst are... read more or long-term alcohol abuse).
Evaluation of Limb Pain
It is particularly important to make sure the person does not have a sudden blockage of an artery because the limb can develop gangrene if there is no blood flow for more than a few hours. The following information can help people decide when a doctor's evaluation is needed and help them know what to expect during the evaluation.
In people with limb pain, certain symptoms and characteristics are cause for concern. They include
Sudden, severe pain
Limb that is cold to the touch or pale
Chest pain, sweating, shortness of breath, or palpitations
Signs of severe illness (for example, confusion, fever, or collapse)
Limb that is suddenly swollen, blistered, or has black spots
Risk factors for deep vein thrombosis, such as recent surgery, bed rest, or a cast on a leg
New nerve deficits, such as weakness or numbness of the affected limb
When to see a doctor
People who have warning signs should see a doctor right away. People without warning signs should call a doctor. The doctor will decide how quickly the person needs to be seen based on the symptoms, age, and presence of other medical disorders. Typically, a delay of several days is not harmful.
What the doctor does
Doctors first ask questions about the person's symptoms and medical history. Doctors then do a physical examination. What they find during the history and physical examination often suggests a cause of the limb pain and the tests that may need to be done.
How long limb pain has been present
Whether pain occurs at certain times or during specific activities
How intense the pain is
Whether the pain is sharp or throbbing
Where the pain is located
What activities trigger or worsen pain
What the person does to relieve pain
What other symptoms (such as numbness or tingling) occur along with the pain
Doctors look for symptoms that may indicate a cause of the pain. Some obvious findings may be very helpful in diagnosing the cause of limb pain. For example, back or neck pain suggests that a nerve root may be affected and fever suggests that the person has an infection. Shortness of breath and a rapid heart rate suggest blockage of an artery by a blood clot that has traveled from a leg to the lungs ( pulmonary embolism Pulmonary Embolism ). An irregular pulse suggests that the person may have a certain abnormal heart rhythm ( atrial fibrillation Atrial Fibrillation and Atrial Flutter Atrial fibrillation and atrial flutter are very fast electrical discharge patterns that make the atria (upper chambers of the heart) contract very rapidly, with some of the electrical impulses... read more ) that has caused a blood clot to travel from the heart to block an artery in the leg.
The painful limb is inspected for color, swelling, and any skin or hair changes. The doctor also checks for pulses, temperature, tenderness, and crepitation (a subtle crackling sensation indicating gas in the soft tissue caused by a serious infection). Strength, sensation, and reflexes are compared between affected and unaffected sides. Blood pressure is sometimes measured in the ankle or wrist of the affected limb and compared with the blood pressure in an unaffected arm or leg. If blood pressure is much lower in the painful limb, it is likely that the arteries in the limb are blocked.
Testing is not needed for all people with limb pain. Doctors can often diagnose some causes of limb pain based on the people's symptoms and the physical examination findings. However, testing is needed in some cases to confirm the diagnosis. For example, doctors may check the ankle-brachial index to diagnose peripheral arterial disease Occlusive Peripheral Arterial Disease Occlusive peripheral arterial disease is blockage or narrowing of an artery in the legs (or rarely the arms), usually due to atherosclerosis and resulting in decreased blood flow. Symptoms depend... read more .The blood pressure is measured in both arms and both legs. If blood pressure in the ankle is lower than that in the arms by a certain amount (less than 90% of arm pressure), blood flow to the leg is inadequate.
Treatment of Limb Pain
The best way to treat limb pain is to treat the underlying disorder. Analgesics such as acetaminophen and nonsteroidal anti-inflammatory drugs can help relieve pain. Sometimes opioids are needed.
Key Points about Limb Pain
In people with sudden, severe pain, blood flow to the limb has often been stopped or reduced and testing must be done quickly.
Symptoms and characteristics found during the doctor's examination usually provide clues to the cause of limb pain.