What the diagnosis actually describes.
The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) defines diabetes simply: a disease that occurs when your blood glucose is too high. Insulin, a hormone from the pancreas, lets glucose leave the bloodstream and enter your cells for energy. In diabetes the body makes too little insulin, makes none, or does not use it properly, so glucose stays in the blood instead of reaching the cells that need it.
NIDDK separates the main forms. In type 1, the immune system attacks the pancreatic cells that make insulin. In type 2, the most common form, the body's cells do not use insulin properly. Gestational diabetes develops during pregnancy. Prediabetes means glucose is above normal but below the threshold for a type 2 diagnosis.
The reason a brain-health practice keeps a page on this: NIDDK states that high blood glucose raises the risk of damage to the eyes, kidneys, nerves, and heart. Nerves are on that list.
Diabetic neuropathy is the neurological complication.
NIDDK describes diabetic neuropathy plainly as nerve damage caused by diabetes, driven over time by high blood glucose and high triglycerides. It comes in four recognized patterns — peripheral, autonomic, focal, and proximal — and more than one can be present at once.
Peripheral is by far the most common: NIDDK reports that up to half of people with diabetes have it, and the CDC notes it usually starts in the feet before involving the legs, hands, or arms.
The foot risk follows directly from the numbness. If you cannot feel a cut, blister, or sore, the CDC points out that you may not notice it, and an unnoticed wound can become a serious infection. Amputation is sometimes necessary, though the CDC states that checking and caring for your feet can prevent it in some cases. Foot exams are not a formality.
- Tingling or a pins-and-needles feeling, usually starting in the feet (CDC).
- Numbness or weakness in the feet, legs, hands, or arms (CDC).
- Pain or increased sensitivity, often worse at night (CDC).
- Risk rises with high blood sugar, years lived with diabetes, overweight or obesity, being older than 40, and high blood pressure or cholesterol (CDC).
What the evidence on thinking and memory shows — and what it does not.
Start with the vessels, because that part is well established. NIDDK states that high blood glucose can damage your blood vessels and the nerves controlling them, and that adults with diabetes are nearly twice as likely to have heart disease or stroke as adults without it. The brain runs on those same vessels.
On cognition, a review by Biessels and Despa in Nature Reviews Endocrinology gathers the epidemiology: meta-analyses put the relative risk of dementia in people with diabetes at roughly 1.73 for dementia overall, 1.53 for Alzheimer's disease, and 2.27 for vascular dementia. The same review describes subtler decrements in type 2 diabetes across processing speed, executive function, and memory, progressing about 50% faster than ordinary cognitive ageing.
Now the honest part, routinely left out. Those same authors report that randomized trials so far do not support the idea that intensive glucose control produces better cognitive functioning, and that type 2 diabetes does not increase the burden of Alzheimer's pathology despite raising the clinical dementia rate. The mechanisms — vascular injury, disturbed insulin signaling, inflammation — remain under investigation. The association is real. A settled causal story with a known fix is not, and any page offering you one is ahead of the evidence.
Your diabetes belongs to your medical team.
Diabetes and prediabetes are diagnosed with blood tests — NIDDK lists the A1C, fasting plasma glucose, oral glucose tolerance, and random plasma glucose tests — ordered and interpreted by a health care professional. Prediabetes is easy to miss: the CDC says more than 2 in 5 American adults have it and that you can have it for years with no clear symptoms, while it raises your risk of type 2 diabetes, heart disease, and stroke.
The CDC's prediabetes guidance is concrete: losing around 5% to 7% of body weight and getting at least 150 minutes a week of brisk walking or similar activity lowers type 2 risk, and the CDC-led National Diabetes Prevention Program exists to support that. Ask your doctor about testing and whether that program fits you.
Read the boundary clearly. Gates Brain Health is a functional neurology practice, and Dr. Randall Gates, D.C., DACNB is a board-certified chiropractic neurologist — not a medical doctor and not an endocrinologist. This practice does not diagnose or manage diabetes, does not direct blood sugar control, and is no substitute for insulin, any other prescribed medication, or the clinician prescribing it. Nothing here is a reason to change a dose. People do call about neuropathy symptoms or memory concerns while their medical team runs the diabetes itself; whether that is a sensible fit gets decided on a call, not in advance.
Two situations that should not wait for an appointment.
Severe low blood sugar is a neurological emergency. NIDDK notes that insulin and certain diabetes medicines — sulfonylureas and meglitinides among them — can drive glucose too low, producing dizziness, lightheadedness, confusion, or irritability, and that when it falls far enough a person may have a seizure or lose consciousness. NIDDK states that severe hypoglycemia is dangerous and needs to be treated right away. Get emergency help; do not wait it out.
Stroke is the second. Since diabetes nearly doubles stroke risk, know the sudden signs — one-sided weakness or numbness, trouble speaking or understanding, sudden vision loss, loss of coordination, or a severe headache with no clear cause. Phone 911 immediately if they appear, and never use this website to report anything urgent.
Short of an emergency, the CDC lists reasons to call your doctor: a foot sore that is infected or will not heal, burning or tingling or pain in your hands or feet that disrupts daily activities or sleep, changes in digestion or urination, and dizziness or fainting.
Questions worth asking when you call.
Bring pointed questions and expect a straight answer about where the limits sit. Save medical details for the phone call or the visit rather than sending them through this website.
- My endocrinologist or primary care doctor manages my diabetes — what specifically would you be looking at?
- What would you not take on here, and when would you send me back to my prescribing clinician?
- How would you coordinate with the doctor running my blood sugar management?
- What could an examination tell us about my neuropathy symptoms, and what could it not?