Q: I understand there is a multitude of sleep disorders, so how do you go about diagnosing what a person suffers from?
A: There are over 80 different sleep disorders. In practice, 80 percent of them are not that common. You make the core diagnosis with a clinical interview of the person with the problem and [their] family members. The history is hard to get [because it concerns times] when people are sleeping. Sometimes, there are some key things that you can pick up that way, like if there is something happening in particular, such as a patient acting out dreams. You have to consider general medical conditions as well and by extension any medications people are taking. Habits are important: anything they take into their body like caffeine, nicotine or alcohol can make a difference; shift work; chronic sleep deprivation by choice [i.e. staying up late to perform other tasks after work] also is important.
Q: What are the most common disorders?
A: Far and away, the most common is probably obstructive apnea. It's a condition in which the upper part of the airway relaxes and actually closes down during sleep. It leads to increased work of breathing, in the setting of lowered oxygen content in the blood. It's often terminated by a gasp or a snort. The interesting thing is I've seen people who don't snore a lot and aren't drowsy during the day who have apnea. It can get difficult to diagnose. We now have a concept that the poster child of apnea is a huge man who makes a lot of noise during sleep and is drowsy during the day, but I have seen an increased number of women who don't snore a lot and don't seem drowsy during the day who have apnea and are not experiencing the same symptoms we see with the guys.
Q: National Sleep Foundation guidelines say everyone needs eight hours of sleep a night. Does everyone really need that much?
A: That's an average and a good thing to shoot for. Sleep debt is cumulative, and there's not evidence that making it up is as good as not losing it in the first place. There's no good evidence that you can actually catch up without consequences. That's supposed to be eight hours of totally efficient sleep. If you have something that is making your eight hours less than efficient, you may still wake up tired. Partial sleep deprivation is really significant.
Q: Are sleep disorders dangerous or simply annoying and inconvenient?
A: They can be all those things. People have been killed sleepwalking. There are short-term and long-term consequences to anything that interrupts your sleep. If it affects your daytime functions, you can be at increased risk for accidents if you are operating heavy machinery. There are long-term consequences to apnea, which include increased risk of heart failure, heart attack or stroke. It causes your heart and lungs to work harder at night and they don't get the rest they need. It fragments nighttime sleep, and that's not good for you either, in terms of wear and tear on the blood vessels. There's no question that hypertension can be made worse, but I don't think that's universally true.
Q: What can you find out by observing a person in a sleep lab?
A: That is an extremely complicated medical procedure. You're continually monitoring brain waves and respiratory effort and air flow and heart rate and oxygen saturation and tone in the muscles, body position, presence or absence of snoring and any other unusual motor activity, like talking in their sleep or acting out dreams. It's an awful lot of data you get from this type of thing.
Q: How much of diagnosis can be made outside a sleep laboratory?
A: What has been found is that [watching the person at home] is not a good indicator of how bad the apnea is or even if it is present, because [the subject and family-member observers] are usually sleeping. What you get confirmation of in a study lab is not just whether apnea is present, but how long it occurs, how long the events are, how disrupted the sleep is, how low the oxygen saturation goes, and whether or not there are any associated heart rhythm problems with that.
Q: Do treatments generally require medicine or behavior modification?
A: It depends entirely on what the problem is. Some we treat with medicines, some with behavior modifications, some with other medical devices.
Q: What types of behavior modifications are beneficial?
A: Caffeine and nicotine are both significant stimulants that can stay in your system for hours. I usually recommend [stopping those stimulants] six to eight hours before you try to sleep. Alcohol is another interesting one. Initially, a lot of people find it tends to make you go to sleep, but it makes apnea worse and as you metabolize the alcohol, it's easier to wake up during the night.
Q: Let's talk about snoring.
A: We make a lot over snoring as a sign of obstruction. We see patients who snore who don't have apnea or have apnea and don't snore. ... You need to be sensitive as to how you feel during the day. Most of us are chronically sleep-deprived to some extent or another. It's not OK to be drowsy when you're still; that's not normal, but they've been tired for so long they don't know that.