Maybe it recently took you a surprising amount of time to remember the name of your beloved sixth-grade teacher. Perhaps you’ve noticed an aging relative is forgetting to go to appointments they’d normally attend. There are various reasons why you might wonder if memory issues are normal or signaling something more serious.

“It is very common for people to have memory concerns, but forgetting things doesn’t always mean it’s a sign of something abnormal like [dementia],” Scott Kaiser, M.D., a family physician and geriatrician at Providence Saint John’s Health Center in Santa Monica, California, tells SELF. But how can you tell the difference? Read on to learn how to distinguish between normal age-related memory decline and signs of dementia.

It’s totally normal to forget things like the name of the street you grew up on as you age.

“The vast majority of people will have some change in their memory with age,” Amit Sachdev, M.D., an assistant professor, neurologist, and director of the Division of Neuromuscular Medicine at Michigan State University, tells SELF.

As excellent as your brain may be, there’s only so much information it can retain over time. If you’re trying to recall something you haven’t thought of in years or the information wasn’t particularly important to you at the time, it’s easy to forget it in order to make room for new, more important information, Dr. Kaiser says.

Your brain also changes as you get older. For instance, you may experience reduced blood flow in your brain or less communication between the neurons that process information, according to the National Institute on Aging. Some parts of your brain also begin to shrink, including those involved with learning. All these changes can translate into a harder time finding words, remembering names, paying attention to things (even if you’ll need to remember them later), and general memory issues.

The key difference is that memory decline related to age typically makes you forget information from a long time ago. Dementia impacts more recent memories first.

Dementia actually isn’t a health condition. It’s a group of symptoms that affect functions related to your memory, cognition, and social skills, according to the Mayo Clinic.

“Dementia causes memory loss that impacts activities of daily living,” Dr. Sachdev says. For example, if a loved one has dementia, they could feel lost in familiar places, forget to pay bills, or repeat questions after forgetting the answers.

That’s not all. Dementia can lead to difficulty communicating, trouble with problem solving, difficulty handling complex tasks, trouble planning and organizing things, issues with coordination, and overall confusion and disorientation, according to the Mayo Clinic. People with dementia can also experience psychological changes like shifts in personality, depression, anxiety, inappropriate behavior, paranoia, agitation, and hallucinations.

One type of dementia tends to be more notorious than others, perhaps because of its prevalence.

Alzheimer's disease, which affects around 5.5 million people in the United States, is the most common cause of progressive dementia in older people, according to the Mayo Clinic says. Its cause isn’t fully understood, but plaques (clumps of a protein called beta-amyloid, which harms brain cells) are often involved, as are tangles in the system the brain uses to transport nutrients.

There are other forms of dementia, per the Mayo Clinic. These include:

  • Vascular dementia: This can happen if the blood vessels that feed into your brain become damaged, typically due to a stroke or some other issue related to these passageways.
  • Lewy body dementia: If this sounds familiar, it may be because it’s the condition Robin Williams reportedly suffered from before his death in 2014. Lewy body dementia happens due to abnormal collections of protein in the brain (Lewy bodies).
  • Frontotemporal dementia: This group of diseases is marked by the breakdown of nerve cells in the frontal and temporal lobes of the brain, which are usually linked with personality, behavior, and language.
  • Mixed dementia: This term describes having a combination of several forms of dementia.

Certain conditions like Huntington’s disease and Parkinson’s disease can cause symptoms of dementia as well, as can traumatic brain injury.

In general, your risk of dementia rises after you turn 65. If you or a loved one is younger than that and having memory issues, don’t jump to the worst conclusion.

This doesn’t mean that dementia is just a normal part of living past 65 or that younger people can’t get dementia, the Mayo Clinic explains. People with Huntington’s disease typically first experience symptoms between 30 and 40, for example. Early-onset Alzheimer’s can also strike as soon as a person’s 30s, but that typically has a genetic link and only affects around 5 percent of people with the condition.

Still, listen to your gut. If you’re dealing with memory loss that concerns you (or if a loved one is), make a doctor’s appointment to get started on investigating the symptoms.