At present, most of the diseases that cause dementia are not able to**, and there is still much to be done to make life easier for people with dementia and their caregivers and families.
What are some common symptoms of brain damage? The brain is a complex and mysterious organ, a source of thoughts, emotions and character. Brain damage can cause changes in a person's mood, personality, and reasoning abilities. However, the diseases that cause dementia are physiological: many of the changes in mental function and behavior in patients stem from structural changes in the brain and changes in the chemicals within the brain. Most of the conditions that cause dementia cause damage gradually, and the effects are not as sudden as a serious stroke or head injury. As a result, the behavioural problems of people with dementia are not easily understood. For example, it can sometimes be difficult to tell whether their personality changes are caused by dementia, especially if they appear normal overall. 
It is important to understand that brain damage and maladaptation to the environment are common causes of behavioral symptoms. The brain is made up of billions of tiny neurons, each of which has connections with other neurons, making it a very complex organ. All the tasks that the brain is responsible for, including thinking, talking, dreaming, walking, listening**, and many other activities, are the result of neurons communicating with each other.
Different areas of the brain are responsible for different tasks, and as a result, damage to different areas can lead to different problems. For example, a stroke may cause a person to be unable to speak because the stroke occurs in the brain's language area, damaging the brain cells needed to speak. Strokes can cause serious brain damage, but it's usually limited to one area of the brain.
However, the damage caused by the disease that causes dementia occurs in multiple areas and affects multiple functions of the brain. The damage caused by stroke will be fully apparent in a short period of time, while Alzheimer's disease will slowly cause more damage, for example, the patient's cognitive function will decline in a way that is difficult to **. As a result, people with Alzheimer's disease can do certain things and some they can't. For example, they can remember things from a long time ago, but they may not remember what happened the day before.
People who have brain damage may do things that others can't understand.
John remembers being angry with his wife, but he doesn't remember the explanation she gave, and even forgot why he was angry in the first place.
If the brain damage affects the patient's ability to perform any of the tasks, then the patient will not be able to complete the rest of the task.
One patient's family member said, "I asked my sister to pour us both a cup of tea, but she ignored me. Half an hour later, she went to the kitchen to pour herself a glass. ”
Mrs. Robinson liked to help out in the kitchen of her eldest daughter's house, but when she went to see her younger, she always sat and pointed. The younger daughter thinks that her mother prefers her sister, and that her mother's refusal to help herself is implying her preference for her sister. In fact, the reason is that Mrs. Robinson was already familiar with the kitchen of her eldest daughter's house before she became forgetful, and she could do things well there, but she was unfamiliar with the kitchen of her younger daughter's house, so she could not do anything well, she did not dare to do anything, she could not even find the plate, she could only point.
The patient's mood also influences their behavior. They often feel lost, worried, anxious, vulnerable, or helpless. They may also realize that they are not doing things well and feel that they have made a fool of themselves. There are also factors that can likewise influence a patient's behavior. When patients don't feel well, their ability to think decreases. 
How should family members or caregivers relate to the patient? When a patient communicates with a caregiver, they first need to hear the caregiver's voice: the first step in communication is perception, i.e., the input of the sound is perceived first. They may repeat what they hear in the moment, but by the second step, which is to memorize and process it in a short period of time, people with Alzheimer's disease may not be able to do it well. Once they can't remember what the caregiver said, they can't respond. If they can only remember and understand a part of the content, then they can only react to that part. For example, the caregiver said to them:"The grandchildren are coming for dinner, you need to take a shower",Some patients may only remember and understand the message "take a bath" and will just go to the shower and forget that their grandchildren are coming for dinner. There are also patients who have no memory or understanding that when the caregiver takes them to the bathroom, they get angry because they forgot that their grandchildren were coming and why they were going to the bathroom. In addition to remembering what is heard, the patient must understand the meaning of the words and evaluate what is heard. As soon as anything goes wrong in the process, they react inappropriately, and they think they've reacted to everything they've heard. In fact, they are simply processing what their ears hear, what their brains record, and what they understand. If the patient's brain messes up with the information, they will "make up the brain" in a way that they can understand. For example, they may think that the caregiver is a stranger, or that they are a young person, or that the caregiver is their father or mother, etc., and give the wrong response. Usually, a calm patient responds calmly, and a grumpy patient responds irritablely, but in any caseTheir responses are based on the information they receive and their own understanding, not necessarily what the caregiver wants to convey to them. The final step is the patient's response. This step can also be problematic: the patient's words may not accurately convey what they mean. It may sound as if the patient is deliberately giving evasive, insulting, or meaningless responsesBut it's actually their impaired ability to express themselves. The information we currently have about this process is still incomplete. Many neuropsychologists are studying the psychological conditions of people with dementia in an attempt to understand these complex cognitive processes. Often, a neuropsychologist or linguist can find out why some people with dementia are depressed. Linguists can sometimes devise solutions. People with dementia say or do things that don't seem to make any sense, are annoying, or they seem to be deliberately causing troubleBut in reality, it's the result of damage to their brains. The patients themselves are actually in pain, and they are trying to avoid these situations as much as possible. The thoughts of people with dementia can sometimes be difficult to understand. Because the brain is so complex, even top specialists can be confused, and many family members have never even been exposed to a neuropsychologist or linguist. So,As much as possible, the patient's problems should be seen as a result of their brain damage, rather than as intentional. While this may not sound like a practical solution, the love, comfort and calmness of the family are very important to the patient. Get information. The more you know about the nature of dementia, the more effectively you will be able to cope with your patient's symptoms. Symptoms vary depending on the specific disease causing dementia, so an accurate diagnosis is crucial. Communicate your concerns to the patient personally. When a person with dementia has mild or moderate brain damage, families can share their grief and worries with them and work together to design memory aids to help them maintain independence. Patients with mild brain damage can benefit from counseling and communication because they can accept and adjust to the reality that they can't accomplish certain things on their own. However, if the patient is not aware of the problem, the family should accept the situation and not argue with them. Solve problems one by one. Many family members have told us that patients have the hardest problems in their daily lives, such as bathing, cooking, and cleaning up after eating. If the family really can't bear it, start with the simplest thing, find something that the patient can change, and then let him work hard to do it. Sometimes, small changes can make a big difference. Get plenty of rest. One of the dilemmas faced by many family members or caregivers is that they do not get enough rest, and some people do not even have a chance to breathe, and they inevitably suffer from both mental and physical torture, and then lose patience and easily behave in annoying behavior. When this happens, family members or caregivers may want to try switching roles and imagining themselves as patients. Excerpt from "Handbook for Home Care for the Elderly with Dementia and Dementia", Hualing Publishing House (illustration from freepik).