The exact length of time a person with severe dementia can live varies from person to person, ranging from 1-2 years or several years depending on care and complications. Severe dementia is mainly characterized by incontinence and complete inability to care for oneself. Patients experience severe loss of judgment, diminished intelligence, memory loss, social cognitive decline, and also psychiatric symptoms such as severe delusions, hallucinations, unprovoked attacks on family members, and even paralysis. If patients become comatose, they are prone to lung infections, pressure sore infections, and increased chances of thromboembolic cardiovascular disease, and patients may die within days to days. Families of patients with severe dementia need to take good care of them and give scientific care according to medical advice to help prolong the expected survival time of the patient.