6 Subtle Signs You Could Use More Sleep (Beyond Just Feeling Tired)

Deep-belly yawns, midday naps, a thirst for caffeine: Some signs of sleepiness are obvious. But since sleep fuels so many processes in the body, tiredness can also be more subtle. Here are six lesser-known signals that you might want to start making deep sleep a higher priority: 

The researchers said a hormone called vasopressin might explain this, as sleep seems to help this hormone do its job of regulating fluid levels in the body.

While lying awake with racing thoughts is no fun, falling asleep as soon as your head hits the pillow isn't the goal either. Ideally, you want to fall asleep within 20 minutes of closing your eyes. Dozing off within this time frame is a sign that your body and mind are ready for sleep but not completely exhausted.

Sex drive is largely dictated by hormones, and quality sleep helps keep these hormones in check. One study in the Journal of Clinical Endocrinology & Metabolism1 found that sleep was important for maintaining healthy levels of testosterone in particular: a sex hormone that gets both men and women in the mood.

When we get a night of less-than-great sleep, sour moods often follow. One small study in Clinical Psychological Science2 found that those who did clock enough hours of deep sleep had, on average, 50% more unwanted thoughts the next morning than those who had a quality night's sleep. On the other hand, getting enough rest seems to promote a positive mood3 and support our capacity for mindfulness.

When we're not getting as much sleep as we should, it can stimulate hunger for certain types of foods. "Poor sleep affects your hypothalamus, the master control center in your brain of hormones like cortisol, epinephrine, and norepinephrine... Not getting enough sleep can also lead to poor eating decisions," board-certified internist Vincent Pedre, M.D., previously wrote of the sleep-gut connection on mbg. He notes that sleep helps curb cravings for high-calorie, low-nutrient snacks like candy bars, chips, chocolates, and other desserts.

Sleep is when our bodies recover from the demands of the day, so when we don't get enough of it, we can't operate at our best physically. If your usual workouts start to feel more difficult, it could be a sign you could use more sleep. "Try getting an extra 30 minutes of sleep every night. You might be surprised just how much better you will feel," says board-certified sleep specialist Michael J. Breus, Ph.D.

Waking up feeling refreshed in the mornings, getting tired around the same time every night, falling asleep quickly (but not too quickly!), and staying asleep throughout the night are all signs that your body has fallen into a healthy sleep rhythm.

It's worth noting that many of these sensations of sleeplessness can also be signs of a more serious medical issue. If they persist or seem to get worse, regardless of how much sleep you get, you'll want to check in with your doctor.

Sleep is nothing to snooze on. Deep, high-quality rest can pay dividends for everything from your mood to your sex drive. It's a gift to yourself that'll keep on giving long after the alarm goes off.