The way to address this begins with evaluating your sleep using the “two Qs,” said pulmonary and sleep specialist Dr. Raj Dasgupta, a clinical associate professor of medicine at the University of Southern California’s Keck School of Medicine. “If you’re getting the good quantity sleep, the next question is, ‘Am I getting good quality sleep?'”
“There are a lot of conditions that cause fatigue, but they don’t necessarily make people feel like they’re ready to fall asleep,” said Jennifer Martin, a professor of medicine at the David Geffen School of Medicine at the University of California, Los Angeles, and president of the American Academy of Sleep Medicine.
These can include chronic pain conditions, metabolic or thyroid conditions, anemia, and chronic obstructive pulmonary disease.
If you’re feeling inexplicable fatigue, “an important first step might just be a routine physical with your family doctor,” Martin said.
2. Sedentary lifestyle
If you’re sedentary, your body can get used to only having to expend low levels of energy — so you might feel more tired than you should when trying to do basic daily activities, Martin said.
3. Anxiety or depression
And sometimes the medications used to treat depression or anxiety can have side effects such as insomnia or blocking deeper stages of sleep, Dasgupta said.
4. Inconsistent sleep
Sometimes our schedules differ on weekdays versus weekends, Barnes said. Schedules can also fluctuate for people with shift-based jobs.
“A very common practice would be to say, ‘OK, well, it’s Friday night. I don’t have to work tomorrow morning, so I can stay up a bit later,'” Barnes said. Maybe you stay up even later Saturday night since you don’t have to work Sunday either, then go to bed earlier on Sunday ahead of the work week.
But by this point, you’ve already adjusted your sleep schedule back by a couple of hours in a short period of time. “This is very much analogous to jet lag,” Barnes said. “That rapid reset doesn’t work very well.”
6. Poor sleep environment or routine
7. Sleep partner problems
“The person (or pet) with whom you share a bed has a big impact on your sleep,” Martin said.
8. Sleep disorders
On that note, sleep disorders are another factor that can dramatically diminish sleep quality, Barnes said.
Someone with sleep apnea might wake up 50 times, 100 times or even more throughout the night, he added.
“Once you’re awake, you’re no longer in the deep sleep and you don’t get to usually drop immediately into the deepest sleep,” Barnes said. “Bringing people out of that deep sleep by waking them up is going to generally result in less time spent in the deepest stage of sleep.”
The ideal way to track sleep quality and quantity — especially if you think you could be diagnosed with a sleep disorder — is undergoing polysomnography at a sleep clinic, Barnes said.
Apps and electronic wearables — such as watches or rings — that measure sleep aren’t as accurate as clinic tests, but still provide sufficient information for healthy adults, Barnes said. “I’d want to know that it was developed and then validated against another, more accurate device.”
CNN’s Lisa Drayer and Sandee LaMotte contributed to this story.