20 Symptoms of Endocarditis to Look Out For
17. Anemia

Chronic endocarditis can lead to anemia of inflammation—also known as anemia of chronic disease. The body, in its attempt to deprive bacteria of iron, alters red blood cell production, leading to fatigue, pallor, and weakness. Hemolysis due to valve destruction or microangiopathic damage can worsen the condition. Anemia in endocarditis is usually normocytic and normochromic, but it may be masked in patients who already have chronic illness. If unexplained anemia coexists with fever, weight loss, or murmurs, further investigation into an infectious cause, including blood cultures and echocardiography, becomes essential.
18. Difficulty Concentrating (Cognitive Fog)

Cognitive fog or trouble focusing isn’t often the first symptom one associates with endocarditis—but it’s common, especially in subacute forms. Chronic infection, poor oxygenation from heart valve dysfunction, and inflammatory cytokines all contribute to mental cloudiness. Patients may report forgetfulness, slowed thinking, or just feeling “off.” In elderly patients, these cognitive changes may be mistaken for dementia or delirium. When paired with fever, fatigue, or heart-related symptoms, cognitive fog should prompt consideration of a systemic infection—particularly endocarditis, which can smolder for weeks before escalating.
