Isheemia

Isheemia is commonly a misspelling of the medical term ischemia, which describes a reduced blood flow to a tissue or organ. Ischemia results in insufficient delivery of oxygen and nutrients required for normal cellular metabolism. If perfusion is not promptly restored, tissue injury or infarction can occur.

Ischemia can affect any tissue but is most often discussed in relation to the heart, brain, gut, kidneys, and limbs. Cerebral ischemia can cause stroke, myocardial ischemia can lead to angina or heart attack, and intestinal or renal ischemia can lead to organ dysfunction. Causes include narrowed or blocked blood vessels due to atherosclerosis, thrombosis, embolism, vasospasm, or systemic factors such as severe hypotension, shock, dehydration, or severe anemia.

Pathophysiology centers on oxygen and nutrient deprivation, which forces cells to switch to anaerobic metabolism, accumulate lactate, and lose energy stores. If ischemia is brief, tissue can recover; prolonged ischemia often results in irreversible cell injury and necrosis. Reperfusion, or the return of blood flow, can sometimes cause additional tissue damage through inflammation and oxidative stress.

Diagnosis and management depend on the affected organ. Cardiac ischemia is evaluated with ECGs, cardiac biomarkers, and imaging, and treated with therapies to restore blood flow when appropriate. Cerebral ischemia may be treated with thrombolysis or mechanical thrombectomy within specific time windows. Prevention focuses on managing risk factors such as atherosclerosis, hypertension, diabetes, and smoking, and using antithrombotic therapies when indicated.