St. Mary’s Hospital Neurologist Dr. Mandira N. Mehra
Many Americans skimp on sleep thinking there’s no harm in missing a few hours here or there to maximize hours spent working or having fun. But, Dean and St. Mary’s Hospital Neurologist Dr. Mandira N. Mehra says routinely missing sleep causes a sleep debt, which has serious effects.
“Sleep is not a luxury, it’s a necessity,” says Dr. Mehra. “It’s the only time your body has to repair and restore itself.”
What happens when you sleep? “Your brain doesn’t just turn off when you go to sleep,” says Dr. Mehra. “Some parts of your brain are very active during your sleep cycles.”
Dr. Mehra says your brain’s glymphatic system is highly active during sleep. Because the glymphatic system acts as your brain’s “drainage system,” getting enough sleep helps your brain remove and recycle toxins, proteins and other items it needs to work properly. Another important process that occurs during sleep is cellular repair. During deep sleep, your brain secretes chemicals that repair your cells after the wear and tear they experience during the day. Your brain also organizes the chaos created by everything you see, hear, taste, touch and otherwise experience during the day. With so many stimuli vying for our attention the brain can’t properly process all information that comes in, so it needs time during sleep to create memories.
“We all have a circadian rhythm, an internal clock that regulates our sleep-wake homeostasis,” says Dr. Mehra. “This is particularly sensitive to internal stimuli and external stimuli from the environment. For example, changes in light exposure, various medications and foods can affect this internal clock rendering us susceptible to sleep variations.”
What is sleep debt?
When you miss out on sleep you create a sleep debt.
“The debt is the difference between how much sleep your body needs and the amount of sleep you actually get,” says Dr. Mehra. “When you build up several hours of debt over the course of several days or weeks, it gets harder and harder to catch up on sleep.”
For many people, sleep debt is a daily reality. The CDC reports that nearly 100 million Americans say they don’t get enough sleep. In a 2009 study in Wisconsin, roughly a quarter of adults report not getting enough sleep in at least 14 days of the past month.
What’s the harm in skimping on sleep?
As your sleep debt grows, you’ll start to notice brain fog. Dr. Mehra says that foggy feeling is caused by changes in how your tired brain functions:
• Sleepiness slows down your thought processes: Sleep deprivation causes lower alertness and concentration. This makes it harder to focus and pay attention, leading to confusion. It is also harder to complete tasks that require logical reasoning or complex thought.
• Sleepiness impairs memory: Research suggests that sleep helps strengthen the nerve connections that make our memories. Without enough sleep, your brain has a harder time making short-term memories. This often leads to forgetfulness.
• Poor sleep makes learning harder: A sleep-deprived brain has trouble focusing, which makes it harder to pick up new information. It also affects your memory, which is essential to learning and retaining new information.
• Sleep deficits slow down reaction times: This is one of the most dangerous side effects of a sleep deficit. Your brain and nervous system has a hard time reacting to the world around you when you haven’t had enough sleep. The National Highway Traffic Safety Administration conservatively estimates that at least 100,000 crashes reported to police are due to drowsy driving. Driving when drowsy is like driving with a blood alcohol content of .08%, which is the legal blood alcohol limit in Wisconsin.
Are there long-term risks to sleep deprivation?
“Long-term sleep deprivation can increase your risk of chronic disease,” says Dr. Mehra. Some of the most common chronic diseases that can be linked to disordered sleep include:
• Obesity: Several studies show a link between short sleep duration and extra body weight. The association is seen in all age groups, but is often seen in children. Sleep is vital for brain development. Insufficient sleep in children could impact the hypothalamus which regulates appetite and energy expenditure.
• Diabetes: Research reported by the CDC shows a link between insufficient sleep and the development of type 2 diabetes. Sleep duration and quality of sleep are predictors of hemoglobin A1c levels, an important marker for blood sugar levels.
• Cardiovascular Disease: Hypertension, stroke, heart disease and irregular heartbeats are more common in people with disordered sleep.
What about medical conditions that interrupt sleep?
“For some people, sleep is simply harder to get because they suffer from a medical sleep condition,” says Dr. Mehra. “While sleep can be harder for these people, it’s not impossible.”
Dr. Mehra says there are 84 recognized sleep disorders, but three affect more people than others: insomnia, sleep apnea and restless legs syndrome. Insomnia is perhaps the most discussed sleep disorder. True insomnia is defined as an inability to initiate or maintain sleep.
Insomnia can lead to excessive daytime sleepiness and how you function throughout the day. Some people suffer from what is called “learned insomnia.” These people are plagued by a fear of being unable to sleep. If you suffer from an inability to fall asleep or stay asleep, talk to your doctor. Different forms of insomnia can be treated with antidepressants or sedatives along with behavioral changes.
Sleep apnea is a common sleep disorder in America. Approximately 200,000 cases of sleep apnea are treated in the United States every year. People with sleep apnea experience an interruption in their breathing while they are sleeping. Sleeping partners report hearing periodic gasping noises and often the disruption in breathing results in a disruption in sleep. Because this disrupts sleep, it can cause excessive daytime sleepiness.
In addition, the disruption in breathing poses other serious health complications. Symptoms should be taken seriously and if you think you may suffer from sleep apnea, you should ask your doctor about it. Different oral devices can help ease symptoms.
Another common treatment is the use of a positive air pressure machine, commonly called a CPAP, which supplies pressurized air flow to your throat. Another common condition that disrupts sleep is restless legs syndrome, which Dr. Mehra says is a neurological disorder.
“The hallmark symptom of restless legs syndrome is an unpleasant sensation in the legs,” she says. “These sensations come with an uncontrollable urge to move your legs.”
Dr. Mehra says the condition is caused by an abnormality in the neurotransmitter dopamine. Typically doctors combine medication that helps normalize dopamine levels with medication that promotes continuous sleep.
What can you do to develop healthy sleep habits?
“Consistent routines help our bodies and minds prepare for sleep,” says Dr. Mehra. She says creating a routine that helps you wind down at about the same time every night can go a long way to preparing your body for sleep. In general, you’ll want to start your bedtime routine about an hour before you want to fall asleep.
Some other tips to build a sleep friendly routine and environment include:
• Avoid caffeine and vigorous exercise within six hours of sleep
• Keep electronics – TV, computer, mobile devices, etc. – out of the bedroom
• Silence or turn off your cell phone when going to bed
• Make sure your room temperature isn’t too warm or cold
• If you can’t fall asleep within 20 minutes of going to bed, get up and read – return to bed only when sleepy
Can you prepare for a schedule or sleep routine change?
When there is a big change to your schedule or routine, it can make it even harder to get enough sleep. But, with a little pre-planning, you can ease the impact a big change – like working a different shift at work– by planning ahead.
“If you know you’ll be having a significant change to your schedule, incremental changes will make the transition easier,” says Dr. Mehra.
She says when you know about a sleep schedule change, start moving your bed time routine up by about 10 or 15 minutes per night at least one week in advance. These slow changes help your body adjust over time, which can make the final change less of a shock to your system.
How much sleep do you need?
Dr. Mehra says sleep needs can depend on the person and their activity level, but in general these are the recommended amounts of sleep a person needs based on age:
• 0-3 months:
14-17 hours each day
• 4-11 months:
12-15 hours each day
• 1-2 years:
12-15 hours each day
• 3-5 years:
10-13 hours each day
• 6-13 years:
9-11 hours each day
• 14-17 years:
8-10 hours each day
• 18-64 years:
7-9 hours each day
• 65+ years:
7-8 hours each day