Moderate and severe dementia are the final two stages of Alzheimer's disease, according to Mayo Clinic. The moderate stage involves growing confusion and forgetfulness, and the severe stage involves losing the ability to communicate or provide basic care for oneself.
People at the moderate stage of Alzheimer's disease often exhibit judgment that is increasingly poor, losing track of the day, their location and even the season. They may pick up things that aren't theirs because they can't differentiate. They may confuse family members for strangers, and they sometimes need help choosing clothing appropriate for an occasion or the weather. Some lose control of bowel movements and urination, and many start developing paranoid suspicions or hearing and seeing things that are not actually there, notes Mayo Clinic.
In the severe stage, Alzheimer's patients lose the ability to talk in coherent sentences. They also need complete assistance with dressing, eating and going to the bathroom. Some need help walking or even sitting with their heads held up. Reflexes become abnormal, and muscles develop rigidity. Over time, the patient can no longer swallow or manage excretory functions, according to Mayo Clinic.
Progression from diagnosis to death can vary anywhere from eight to 25 years depending on the patient. A frequent cause of death is pneumonia due to impairments in swallowing, which send beverages and food particles into the lungs, causing infection, reports Mayo Clinic.