Every morning, you go for a run around the neighborhood. Today, as you’re on your way home at the end of the run, you can’t remember whether to turn left or right. Is this an age-related memory lapse or the first signs of something more serious?

While many people experience occasional memory lapses as they age — such as forgetting names or appointments — 10 to 20 percent of people over age 65 develop mild cognitive impairment. MCI could be caused by a wide range of things, from poor sleep, stress, hormonal changes and treatable health issues, to irreversible brain health conditions like Alzheimer’s disease. In all of these cases, MCI brings noticeable issues with memory and thinking. While some cases do progress to dementia, MCI can be treatable depending on the underlying cause. So identifying its early signs, seeing a specialist, and pressing for insight into what’s causing your MCI is hugely important.

Here are some science-backed indicators that you should talk to a doctor about the possibility of MCI. 

Friends and family members also notice the changes

Age-related cognitive decline is very subtle. While you may notice the changes, those around you likely won’t be able to tell something is off. Even cognitive tests used by neurologists aren’t designed to detect age-related decline.

In contrast: With MCI, loved ones might notice lapses in your memory and thinking — while you might not. They might see that you’re forgetting to pay bills more often, getting uncharacteristically disoriented, or having more trouble remembering things than usual. 

“What we hear when we talk to people’s families is that people may be repeating themselves,” Dr. Sarah Kremen, a neurologist at UCLA, explained. “They don’t realize that in conversations, they’re telling the same stories.” 

Challenges with memory and learning new things

While 40 percent of older adults experience some memory loss, MCI involves more distinct challenges with retaining information and learning new things.

For example, with age-related cognitive decline, remembering the name of someone you recently met, or recalling the date of a doctor’s appointment, might take longer than usual. But with MCI one may not remember meeting a new person or setting up that doctor’s visit at all.

Memory issues that impact daily life

Unlike typical age-related memory slips, MCI can interfere with everyday life.

“Oftentimes, there’s a lot of misplacement of small items like keys, sunglasses or your phone, and not remembering where you put them down,” said Kremen. “There’s that constant search everyday to figure out where they were put.”

Someone living with MCI may forget to pay bills. They’ll become more vulnerable to financial scams. People with MCI are also more likely to withdraw from hobbies and social activities. 

When should you see a doctor?

If you’re concerned about your cognitive health, see a doctor. Even if there’s nothing wrong, you’ll have a baseline cognitive assessment that could help identify decline later on.

Doctors take your medical history, run blood tests, and a neuropsychological test to determine whether you have MCI. In some cases, MCI could be caused by other medical conditions or hormone deficiencies that could be picked up by a blood test and treated. 

In other cases, MCI could lead to the onset of Alzheimer’s or another type of dementia. Early diagnosis means more time for planning, making lifestyle changes to boost cognitive health, and potentially participating in clinical trials for new treatments.