Marri Horvat, MD has a background in neurology and currently practices at Cleveland Clinic’s Sleep Disorder Center.

Read the Q&A with Dr. Horvat below.

WAM: How do we know when it’s time to sleep? Is it our bodies or our brains that make us so tired we need to close our eyes and nod off?
Dr. Horvat: Both your body and your brain work together to tell you when it is time to go to sleep. Your brain gets input from things around you such as light and darkness, and this triggers certain hormones to be made that help you fall asleep or wake up. Your body will give you signals for when it is time to go to sleep. Typically, those signs consist of yawning, your eye lids becoming heavy and even your head bobbing as though you will fall asleep.

WAM: Over 50 million Americans report problems with sleep. What are the consequences of having sleep disturbances on overall health?
Dr. Horvat: This depends on the reason your sleep is disturbed. If you have a medical condition such as sleep apnea that is disturbing your sleep, this can lead to an increased risk of heart disease, stroke and even dementia. We know that generally, patients who do not get enough sleep (typically 7-9 hours a night) have an increased risk of developing high blood pressure, obesity, diabetes, difficulty concentrating, mood disorders as well as worsening seizure and migraine frequency.

WAM: Contrary to what many of us think, it turns out there is a lot of activity taking place inside our brains during sleep. What is going on—and how is it affecting our long term brain health?
Dr. Horvat: When you are sleeping your brain does remain active, although to a lesser degree. It continues to regulate things like breathing, blood pressure, heart rate, temperature, as well as the production of hormones and other substances throughout the body. Your brain is also working to consolidate new learning and memories while you are sleeping. There is some data to suggest that during sleep your brain is also working to remove waste products that build up during the day. This theory proposes that decreased sleep decreases how much waste we can remove, and that the buildup of these waste products can be toxic to neurons and possibly lead to long term consequences such as Alzheimer’s.

WAM: What does sleep have to do with helping us process memory, and is there any correlation between memory issues due to lack of sleep and those that develop as a result of Alzheimer’s?
Dr. Horvat: We do not have a clear cut idea of how sleep helps memories, but it is thought that during sleep your brain processes these memories and helps turn events and information in to long term memories. We know that sleep deprivation overall can have a profound impact on memory, processing information, and maintaining attention. Several studies have seen an increased risk of developing dementia in adults who consistently get six hours or less a night. We do not know whether these sleep changes contribute to the disease or simply reflect early symptoms of the disease.

WAM: What’s the most exciting thing you’ve learned about the power of sleep?
Dr Horvat: The most exciting thing is simply how much better you can feel with a good night’s sleep. The difference in your ability to think, regulate your mood, interact with people, and even perform day to day activities is astronomical after sleeping well.

WAM: For the 50 million Americans who report sleep disturbances: what tips do you have to help them get a good night’s rest?
Dr. Horvat: This depends on why they are not sleeping well in the first place. If there is concern that a medical condition could be the cause of sleep disruption (such as sleep apnea, thyroid issues, chronic pain, etc.), talking to your medical provider is the first step. In general, sleep hygiene is a good place to start for many of us. Some specific tips include only using your bed for sleeping or sex. You should not be watching TV, doing work or reading in bed as this starts to condition your brain to think of your bed as a place for being awake instead of asleep. Limit screen use (phones, tv, iPad) to 1-2 hours before bed. Do not have screens in your bedroom if possible (if you have a clock, set the alarm and then turn it away from you). Do not drink alcohol or caffeine 3-4 hours before your bedtime. Keep a consistent bedtime and wake up time, even on your days off. Try not to nap during the day.