Biden's health is making headlines. Here's a guide to cognitive tests, age-related decline and more medical terms, defined by experts.

Joe Biden
President Biden at the debate on June 27. (Kyle Mazza/Anadolu via Getty Images)

At 81, President Biden is the oldest sitting president in history. After his debate performance on June 27, which was described as "poor" by 63% of Americans in a Yahoo News/YouGov poll, concerns have been raised about his age, memory and movement. To help navigate headlines about Biden and his health, we've compiled a guide to terms being used and what they mean, defined by experts and put into context.

Cognitive tests are basic screening tools that can quickly check how well the brain is functioning and are typically used to assess whether a patient is having a problem with their ability to think or remember things. The tests assess a broad range of cognitive abilities, including memory, attention, executive function (such as decision-making, judgment) and language, Nichol Castro, a dementia researcher and assistant professor at the University at Buffalo, tells Yahoo Life.

The MoCA (Montreal Cognitive Assessment) test is one example of a cognitive test. Other common cognitive tests include the 10-minute Mini-Mental State Examination (MMSE) and Mini-Cog, which takes three minutes and involves having subjects recall a three-word list of objects and drawing a clock with hands that shows a specific time, according to Medline Plus.

The Mini-Mental State Examination is a quick test that screens for cognitive impairment, such as dementia, and takes about 10 minutes to complete, per Medline Plus. It involves asking a subject the date, having them count backward and asking them to identify everyday objects like a pencil or watch.

The Montreal Cognitive Assessment is “a very short screening test for cognitive abilities,” Castro says. The test is 30 questions long and involves tasks like drawing a clock, copying a picture of a cube and identifying pictures of animals. Outcomes of this test may be used to inform decisions about whether more extensive cognitive testing is needed, Castro says. Dr. James Powers, professor of medicine in the division of geriatrics at Vanderbilt University Medical Center, explains that typically means being referred to a neurologist who may do longer tests called neuropsychological testing to check your ability to plan, solve problems and make decisions, to learn more about how well your brain is functioning.

“Oftentimes, a person will complete a MoCA several times across months or years to track their cognitive abilities,” Castro says. Doctors will typically recommend this assessment when they’re concerned about a person’s cognitive impairment or decline, such as memory loss or trouble concentrating or following instructions. CNN’s Sanjay Gupta recently called on Biden to take this test, along with other cognitive assessments, which Trump took back in 2018.

Gupta also called on Biden to undergo “movement disorder testing.” These tests can help diagnose movement disorders, which are neurological conditions, such as Parkinson’s. They assess a person’s physical movement abilities, Castro says. This might include movement in the arms and legs, along with the fingers. “Speech also requires movement, so assessing facial and mouth movement might also be assessed,” Castro says.

Memory lapses are moments of forgetfulness, Powers tells Yahoo Life. “There are word-finding difficulties and name-finding difficulties that are common as we get older,” he says. “That’s acceptable and not a diagnosis of dementia.” Memory lapses that could signal dementia include things like forgetting to pay bills and forgetting where you’re going when you’re driving, he says.

"It is understandable for individuals to experience changes in their memory throughout their lives," Lauren Snedeker, assistant professor and coordinator for the aging and health certificate program at the Rutgers School of Social Work, tells Yahoo Life. "I like to think of our memory as a studio apartment that we live in for a long time, and inevitably, we pack away a lot of things in that apartment that might take a moment to retrieve. So it could take a moment to recall a word or a name. This alone does not necessarily mean the presence of Alzheimer's disease or another dementia-related illness."

During a recent White House briefing, press secretary Karine Jean-Pierre said that Biden is not being treated for Parkinson’s disease and is not on medications for the condition. An expert in Parkinson’s disease has visited the White House eight times in eight months, according to multiple news outlets, including the New York Times, NBC News and others. White House physician Dr. Kevin O’Connor explained the doctor was visiting other staffers and stated that the president hasn’t seen a neurologist outside of his annual physicals. Parkinson’s disease is a brain disorder that causes unintended or uncontrollable movements, like shaking, stiffness and trouble with balance, per the National Institute on Aging (NIA).

Mild cognitive impairment is a condition that happens when older adults have more memory or thinking problems than other people their age, per the NIA. The risk of developing mild cognitive impairment increases as you get older and can include symptoms like losing things often, forgetting to go to events or appointments or having more trouble coming up with words than other people of the same age, according to the NIA.

Overall, doctors stress that forgetfulness is common as people get older. “I would recommend seeing a doctor when the forgetfulness starts to interfere with one's ability to do everyday activities safely,” Castro says. “There are lots of things that can cause forgetfulness than just aging, so it's important to rule out other possible causes.”

Age-related decline refers to a series of subtle changes that happen naturally as people age, such as a slower thinking speed and attention span. “An older adult might have lower cognitive ability as compared to a younger adult,” Castro says, adding that “many times, age-related decline is expected.” Age-related decline is also not the same as dementia, Powers says, or mild cognitive impairment.

Some news outlets described Biden’s appearance as “frozen” or “stiff” during the debate. Frozen-mask face is not an official medical term, but it's often used by medical professionals and others, typically in the context of Botox treatments, which use a toxin to paralyze facial muscles, or movement disorders like Parkinson’s disease, for which the White House doctor stated Biden is not being treated.

A neurologist is a medical doctor who specializes in diagnosing, treating and managing disorders of the brain and nervous system, according to the American Academy of Neurology. While neurologists may assess patients for signs of cognitive decline and dementia, many family physicians can also do this. As part of his annual physical, Biden was seen by a neurologist. The White House doctor confirmed that Biden hasn’t seen a neurologist outside of these yearly physicals and noted in his February 2024 report that there were no indications of any neurological disorder, including Parkinson’s disease.

The term “sundowning” came up recently during a Fox News segment discussing President Biden. But this refers to people with Alzheimer’s — a condition that the president has not been diagnosed with — who are more restless, agitated, irritable or confused around late afternoon and early evening, according to the NIA. It’s not entirely understood why this happens but may be linked to fatigue, depression, hunger or thirst or boredom, the NIA says.

An aneurysm happens when part of an artery wall weakens, allowing it to abnormally balloon out or widen, per the American Heart Association. Aneurysms can happen in different parts of the body, including the brain. Biden suffered from two life-threatening brain aneurysms in 1988. A reporter brought up the term hydrocephalus during a recent White House press briefing — referring to fluid build up deep within the brain, which can be a complication after an aneurysm — but press secretary Jean-Pierre stated it’s not in the medical report nor is it something the president has.

An annual physical is a yearly checkup with a medical provider. “This is a review of all of the systems of the body,” Powers says. It includes things like a doctor listening to a patient’s heart and lungs and, when a patient is older, asking if they’ve had any recent falls and checking for dementia warning signs. Patients may also be checked for walking ability and vision and asked how well they are able to care for themselves, Powers says. However, presidential annual physicals are more thorough and involve examinations by multiple specialists in neurology, cardiology, orthopedics, sleep medicine and more.

Walter Reed National Military Medical Center is a military medical center in Bethesda, Md., which isn’t far from Washington, D.C. It’s a Navy medical center that houses medical care, Navy medical training, Navy research and a medical library in one location, according to the Walter Reed website. The organization has provided medical care for several U.S. presidents, including President Biden, who receives his annual physical exam at the medical center, most recently on Feb. 28, 2024.