Dementia starts in the brain but over time reaches other parts of the body. It harms brain cells and blood vessels that carry oxygen and nutrients leading to problems with thinking memory movement and basic body functions like breathing and digestion.[1]
In the early stages dementia mainly affects thought and memory causing confusion and trouble speaking. As it worsens the brain loses control over movement making falls more likely. This happens because different types of dementia hit specific brain areas. For example Alzheimers damages the hippocampus which handles memory while vascular dementia cuts blood flow from strokes.[1]
Breathing and lungs take a big hit in later stages. People with dementia often have trouble swallowing so food or liquid slips into the lungs causing pneumonia the top cause of death. Weak muscles and a poor immune system make fighting infections hard. You might see shallow breaths fever or more confusion as signs.[1]
The heart and blood system suffer too. Brain damage disrupts circulation leading to low blood pressure and irregular heart rhythms. In final stages blood flow weakens causing cold skin or blue lips.[1]
Digestion slows down as dementia advances. The brain no longer signals the gut well so eating becomes hard and constipation or weight loss follows. Kidneys play a role here too. Poor kidney function raises levels of dementia markers like tau and amyloid in blood tests even without real brain damage. This can confuse doctors but weak kidneys speed up symptoms if markers are already high.[2]
Blood cells change in dementia patients. Studies show drops in energy molecules like ATP mostly made in red blood cells. This hints at cell power failure from brain-wide stress. Certain blood fats also fall which might hurt brain protection against damage.[3]
Other organs feel indirect effects. Sleep problems linked to dementia cut oxygen to the brain and body harming small blood vessels and memory areas. Treating these can help organ health and slow decline.[5] Aging adds kidney and bladder issues making waste removal tougher.[4] Skin breaks down from bed rest leading to sores and infections that spread to blood.[1]
These changes show dementia as a whole body issue not just brain trouble. Keeping organs healthy through care can ease suffering.
Sources
https://myhometouch.com/articles/how-does-a-person-die-from-dementia
https://alzheimersweekly.com/kidney-health-and-alzheimers-why-your-kidneys-matter-in-alzheimers-biomarker-testing/
https://www.pnas.org/doi/10.1073/pnas.2022857118
https://www.bangkokhospital.com/en/bangkok/content/10-risk-of-deterioration
https://www.nebraskamed.com/health/conditions-and-services/neurological-care/preventing-alzheimers-disease-and-dementia-by
https://pmc.ncbi.nlm.nih.gov/articles/PMC12751288/
