Does endocarditis usually cause many symptoms?

Yes: Endocarditis, or infection of a heart valve, is a serious illness. In its acute form, there may be high fever, chills and sweats, generalized weakness, arrhythmias and heart failure. The subacute form is subtler and may gradually cause anemia, weakness, night sweats, weight loss, fatigue, depression and eventually heart failure. Either form is potentially lethal. If suspected, it needs evaluation.