Multiple causes.: Anemia, infection, hyperthyroidism, heart failure, valvular heart disease, autonomic dysfunction, pericarditis, myocarditis. Rare causes would include neuroendocrine tumors such as a pheochromocytoma. It merits a careful history and physical exam, ecg, chest x-rays and some routine blood tests.
Answered 1/1/2014
4.6k views
2 doctors weighed in across 2 answers
A doctor has provided 1 answer
A doctor has provided 1 answer
3 doctors weighed in across 2 answers
90,000 U.S. doctors in 147 specialties are here to answer your questions or offer you advice, prescriptions, and more.
Ask your question