Brief Answer:
Needs investigations to find cause.

Detailed Answer:
Hello,
Thanks for posting your query.
The presence of extreme pain in one leg with a history of blood clots can be due to a deep vein thrombosis. This can be detected on a color doppler study of the legs.
The treatment involves medicines like coumadin and heparin. These should be started after consulting her physician.
Other causes that need to be ruled out after the clots are ruled out are-
1.Experiencing pain in leg indicates a vascular problem also.The pain may be caused by claudication caused by peripheral arterial disease (PAD), narrowing of the arteries that carry blood to the leg muscles.
2.Peripheral neuropathy- This can occur from direct nerve irritation or from a medical illness like diabetes, thyroid imbalance, etc.Chronic illnesses like alcoholism, cancer, and vitamin deficiencies may also result in nerve pain that often affects legs. There are some illnesses that cause leg weakness that may be associated with complaints of leg pain, like Guillain-Barré syndrome and multiple sclerosis.
3. Muscle pain: Muscle pain or myalgia is a common cause and may be due to overuse (mild trauma) or associated with the generalized aches and pain of an infection.
4. Muscle cramps: Muscles may cramp, causing significant pain. This may be due to a lack of stretching or an imbalance of electrolytes in the bloodstream. You need to get her serum sodium, potassium, calcium and magnesium levels checked.
All the above causes can be ruled out by your physician after some tests and examination.
I hope this answers your query.
In case you have additional questions or doubts, you can forward them to me, and I shall be glad to help you out.
Wishing you good health.
Regards.
Dr. Praveen Tayal.
For future query, you can directly approach me through my profile URL http://bit.ly/Dr-Praveen-Tayal

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