Worried that a loved one’s forgetfulness, confusion and fuzzy thinking may herald the onset of Alzheimer’s disease? You owe it to him or her — and yourself — to get a quick check for brain-draining health conditions and other causes that seem like Alzheimer’s but with one BIG difference: Many of these mind-altering problems are treatable and even reversible.

A recent report looked at nearly 1,000 people with dementia and found that up to 30 percent didn’t have Alzheimer’s disease; many had what are treatable medical conditions or negative reactions to medication. Those include:

Vitamin deficiencies: Extremely low levels of folic acid, niacin or vitamins B-1, B-6 or B-12 can cause Alzheimer’s-like symptoms. Blood tests can determine deficiencies. The elderly are at particular risk for low levels of B-6 and B-12, and may need regular “booster” shots to maintain healthy levels. (If you give extra B-12 to someone who has both memory loss and normal levels of B-12, you can reduce memory problems.)

Normal pressure hydrocephalus (NPH): Caused by a buildup of cerebrospinal fluid in the brain, NPH symptoms include difficulty walking, incontinence and trouble concentrating and making decisions. Draining the fluid via a shunt can relieve pressure on the brain and, frequently, return a person to his or her former self.

Depression: Insist on a depression evaluation before your doctor makes an Alzheimer’s diagnosis. Thinking and recall can improve with treatment for depression.

Urinary tract infections: A chronic or frequent bladder infection may trigger delirium in the elderly. Treat the infection, and the mental symptoms go away.

An underactive thyroid: A metabolic slowdown due to an underachieving thyroid gland can leave you fatigued, weak, depressed and forgetful. Blood tests of thyroid hormone levels can reveal the true cause: ­hypothyroidism, not Alzheimer’s.

Reaction to anticholinergic drugs: Some medications used to treat depression, anxiety, acid reflux, Parkinson’s disease, allergies and overactive bladder may trigger dementia-like side effects. These drugs block acetylcholine, a brain chemical that helps send signals between neurons. Alzheimer’s patients also have depressed levels, which contributes to their confusion and memory loss. (That’s why some medications that slow the progression of Alzheimer’s work by boosting acetylcholine.)

Reaction to digoxin: A medication used to slow your heart rate if you have atrial fibrillation or heart failure, digoxin has been known to reduce brain function; this may trigger ­dementia-like symptoms.

In addition to getting a proper diagnosis and prompt treatment for symptoms of memory loss, you can take these six steps to keep your brain cells humming a happy tune:

1. Walk 30 minutes daily. Regular physical activity is the most important step you can take to prevent ­dementia.

2. Cultivate calm with meditation, yoga, journal writing, breathing exercises or guided imagery.

3. Pack your diet with fresh produce and brain-friendly omega-3 fatty acids from salmon, trout or 900 milligrams of supplemental DHA daily. Protecting your cardiovascular system keeps the brain supplied with the nutrients and oxygen it needs and reduces the risk of stroke.

4. Aim for brain-friendly levels of cholesterol (HDL above 60, LDL below 100, triglycerides below 100), blood pressure (115/75) and blood glucose (90-100 fasting). A low-sodium diet, meditating 10 minutes a day, avoiding saturated and trans fats, and daily physical activity will help you hit those targets.

5. Bolster memory skills by playing brain games and being a lifelong learner. Try learning a new language, tackling a new project or interacting with new people and new situations as often as possible.

6. Guard against head injuries: Avoid standing on rickety chairs or ladders, teetering high heels or cluttered stairs, and always wear a seatbelt. And if you do bump your noggin good and hard and then down the road have symptoms of confusion or memory loss, get to a doctor, pronto!

The You Docs — Mehmet Oz, host of “The Dr. Oz Show” and Mike Roizen of Cleveland Clinic — are authors of “YOU: Losing Weight.” To submit questions, go to www.RealAge.com. A King Features syndicate.