 [ Symptoms ] i have been having breathlessness and dizziness which has been almost constant i am extremely fatigued and have had occasional chest pains [ Disease ] conditions that can present with recurrent episodic fever or elevated body temperature fatigue enlarged lymph nodes palpitations could be due to   autoimmune conditions endocrine disorders like hyperthyroidism infectious mononucleosis viral infections chronic granulomatous conditions like   tuberculosis sarcoidosis brucellosis etc and many others hence it is more likely that your symptoms could be due to chronic medical conditions which can be determined only after proper physical examination evaluation of your medical history and and a few diagnostic tests please consult a doctor specialist in internal medicine who can give you proper opinion