Doctors misdiagnose a patient with Alzheimer’s disease at alarmingly high rates, when the true cause may be a different (and often treatable) disease. In 2011, researchers conducted autopsies on the brains of 211 men who had been diagnosed with Alzheimer’s while they were alive. They found that nearly half of the brains did not possess the necessary pathology to meet an Alzheimer’s diagnosis . A 2012 study reported similar misdiagnosis rates by physicians at the National Institute on Aging’s Alzheimer’s Disease Centers .
An incorrect Alzheimer’s diagnosis can cause a person to pay $9,500 to $14,000 annually in unnecessary medical procedures and medications . Even worse, it may result in the true cause of the dementia symptoms going untreated, hastening the rate of cognitive decline. To give you the tools to reduce the risk of a misdiagnosis, I’ve compiled this list of ten common conditions that can mimic the symptoms of Alzheimer’s disease. If you or a loved one has been diagnosed with Alzheimer’s disease, be sure that you request tests to rule out these other possibilities.
1. Medication side effects
More than 100 medications can have side effects resembling symptoms of Alzheimer’s. These include a wide variety of common meds including Benadryl, Ambien, Valium, Xanax, and Lipitor . It is particularly important to inform your doctor if you are on anticholinergic drugs, which include many antihistamines, antipsychotics, antidepressants, and muscle relaxants, among others . These drugs block the function of a neurotransmitter called acetylcholine, which can lead to cognitive impairment .
2. Normal pressure hydrocephalus
The central nervous system is surrounded by cerebrospinal fluid, which cushions the brain and regulates cerebral blood flow. For unknown reasons, cerebrospinal fluid can sometimes build up in the brain cavities (ventricles) and cause them to swell, resulting in a condition called normal pressure hydrocephalus (NPH). The symptoms of NPH include progressive dementia, difficulty walking, and urinary incontinence . According to the Hydrocephalus Association, NPH affects an estimated 700,000 Americans, though only 1 in 5 of these people receive the correct diagnosis . As many as 10% of patients diagnosed with Alzheimer’s or other forms of dementia may actually have NPH . This condition is easily detected using brain scans and can often be treated by surgically draining the excess fluid from the ventricles. Additional reading on NPH: , , 
3. Vascular dementia
Vascular dementia is the second most common form of dementia after Alzheimer’s. It is caused by a stroke, multiple “mini strokes,” or other cardiovascular disturbances, and can cause similar symptoms to Alzheimer’s . A 2013 study found that 17% of vascular dementia patients were previously given an incorrect diagnosis for Alzheimer’s disease, which led to significantly increased medical costs . Vascular dementia is very difficult to distinguish from Alzheimer’s, and the possibility of misdiagnosis should be considered if the patient has risk factors such as high blood pressure, diabetes, or smoking. There is currently no cure for vascular dementia, but steps may be taken to improve cardiovascular health and reduce the risk of further cognitive decline .
4. Vision or hearing loss
Cognitive evaluations such as the Mini-Mental State Examination (MMSE) may yield an incorrect diagnosis of Alzheimer’s disease if a patient is experiencing undiagnosed vision or hearing loss. Studies have shown that individuals with visual  or auditory  impairments score lower on the MMSE, despite being cognitively normal. Both of these conditions are common among the elerly population. Studies estimate that among individuals over the age of 70, 18% are visually impaired, 33% are hearing impaired, and 8% are both visually and hearing impaired . Regular vision and hearing exams could not only prevent an incorrect diagnosis but also improve the overall quality of life for these patients , .
Depression can often mimic the early symptoms of Alzheimer’s disease. These include mood changes, withdrawal from daily activities, sleep disruptions, and difficulty concentrating . Depression affects more than 1 in 20 elderly adults and the risk may be increased by the death of a spouse or chronic illness, as well as certain medical or psychological conditions . The symptoms of depression can often be improved through a combination of medications and psychotherapy.
6. Thyroid problems
The thyroid gland produces hormones that regulate metabolism and other body functions. The American Thyroid Association reports that 12% of Americans will develop thyroid problems in their lifetime, and more than half of them are unaware of their condition. Both hypothyroidism and hyperthyroidism can have symptoms resembling Alzheimer’s, including forgetfulness, mood changes, and sleep disturbances. Thyroid problems are often treatable but can cause serious complications if left undiagnosed .
7. Vitamin B12 deficiency
Vitamin B12 plays multiple important roles in the nervous and circulatory systems. It is most commonly found in meat, fish, and dairy products. As many as 9% of Americans are deficient in this essential nutrient . Risk factors include a vegetarian or vegan diet without B12 supplements, heavy alcohol consumption, and long-term use of acid-reflux medications. Vitamin B12 deficiency can lead to dementia and changes in mood or personality, which may be mistaken for Alzheimer’s . Individuals with an Alzheimer’s diagnosis might consider requesting a blood test for B12 levels, or increasing their intake of B12 in the form of supplements, fortified cereals, and B12-rich foods to see if their cognitive symptoms improve.
8. Urinary tract infection
Urinary tract infections (UTI’s) are the most common bacterial infection in the United States. They primarily affect women; nearly half of all women will experience at least one UTI in their lifetime . When diagnosed correctly, UTI’s are easily treated using antibiotics and rarely cause complications. However, the little-known neurological symptoms can result in a misdiagnosis as Alzheimer’s. An elderly person with a UTI is at an increased risk of experiencing delirium, which is characterized by sudden behavioral changes such as confusion, agitation, fatigue, or delusions. Be suspicious of Alzheimer’s-like symptoms if they are accompanied by symptoms of a UTI, which include frequent, painful urination and discolored or foul-smelling urine .
9. Sleep disorders
We all know the importance of getting 8 hours of sleep each night, but few of us are aware of just how much sleep depravation can affect our cognitive function. A 1999 study reported that 1 in 5 individuals over the age of 65 experience sleep disturbances, though only a minority seek treatment . Sleep disorders such as sleep apnea, chronic insomnia, and restless leg syndrome can lead to fatigue, difficulty focusing, irritability, and memory loss . These conditions can be easily detected by visiting a sleep clinic.
10. Gluten allergy
This might be the most surprising item on this list: a simple dietary change can completely reverse the symptoms of some people’s dementia. Celiac disease is an allergic reaction to gluten, a protein found in wheat, barley, and rye. Celiac was once believed to be rare, but is now classified as one of the most common autoimmune conditions. The University of Chicago’s Celiac Disease Center estimates that 1 in 133 people have celiac disease, of whom an astounding 97% remain undiagnosed . Though people with celiac can live a healthy life on a gluten-free diet, undiagnosed celiac disease can have serious and even fatal consequences, including progressive dementia and other neurological conditions . For individuals with celiac-induced dementia, switching to a gluten-free diet might completely reverse their symptoms .