Drowsiness in the elderly with cerebral thrombosis may be a sign of cranial hypertension, cerebral thrombosis involving the brain stem, and other complications. 1. Cranial hypertension: if the cerebral thrombosis is a large cerebral infarction, serious edema occurs after the onset of the disease, resulting in increased pressure in the brain, which can lead to impaired consciousness, drowsiness and other manifestations. 2. Cerebral thrombosis involving the brainstem: cerebral thrombosis involves the brainstem and damages the reticularis superior activating system of the brainstem, which in turn leads to drowsiness. 3. Other complications: if there is serious lung infection, it may lead to cerebral ischemia and hypoxia, which may lead to aggravation of consciousness disorder and drowsiness. When the elderly with cerebral thrombosis experience drowsiness, they should go to the hospital in time for consultation and treatment.