Everything that happens according to nature ought to be considered healthy,” wrote Cicero, the Roman statesman. Our bodies follow natural cycles or rhythms—or at least they were intended to. In contemporary society, with the realities of working, traveling, and all the possibilities for distraction and entertainment that are regularly set before our eyes, it’s difficult to realize that a vast, orderly universe exists all around us, operating according to an intricately structured, almost symphonic rhythm. We may try to ignore that rhythm, but it still asserts itself even through the static of everyday life.
Your own sleep/dream/wakeful cycle is, or should be, an expression of this pervasive natural harmony. It can be seen almost everywhere, if one takes the time to look. Earth rotates on its axis every twenty-four hours. It takes 365 ¾ days to revolve around the sun. The moon takes twenty-eight to twenty-nine days to revolve around Earth. Tidal rhythms express gravitational effects of the sun and the moon. All this is on a grand scale, of course, and modern science has only recently begun to recognize the full extent to which these cosmic rhythms have a counterpart within the physiology of every human being. For instance, there is evidence that the point in her monthly cycle at which a breast-cancer patient undergoes surgery is a tremendously important factor in determining the outcome of her treatment. There is also important evidence that illnesses such as clinical depression are dramatically influenced by seasonal changes and even by different times of day.
In order to enjoy perfect sleep it is essential to understand the extent to which the cadence of our internal experience is influenced by the larger rhythm surrounding us, just as a dancer will be drawn to move in time with the beat of an orchestra. In fact, it’s not an exaggeration to say that the internal biological rhythm that each of us perceives as his or her own is actually an expression of the external beat of nature. In other words, these external and internal rhythms are just two expressions of the same carefully ordered natural cycles. These cycles are found throughout the plant and animal kingdoms and have even been observed in isolated cells and unicellular organisms.
For example, studies have shown that certain plants, sensitive to the cycle of day and night, can be placed in a dark room for days at a time and still continue to open and close their leaves according to the cycle of day and night, though they have no direct exposure to sunlight. This demonstrates just how deeply these basic cycles are ingrained in every aspect of nature.
In terms of these cycles’ influence on our everyday lives, there’s one particular well-documented phenomenon that deserves our close attention. Scientists call it circadian rhythm, the pattern of biological cycles that recurs at approximately twenty-four-hour intervals. Many of your body’s vital signs are governed by circadian rhythm: Neurological and endocrine functions, for example, follow a twenty-four-hour cycle, as do temperature fluctuations, hormone and enzyme production, electrolyte excretion, and sleep/wakeful cycle.
The importance of circadian rhythm was first established more than thirty years ago during a series of experiments in the basement of a Munich hospital. A group of volunteers was placed in a windowless room, isolated from all external clues as to the time of day or the day of the week. They were allowed to establish and follow their own schedules for eating and sleeping. This study and later ones revealed that the human body operates on a cycle of approximately twenty-five hours.
This is very significant, because it suggests that if our internal pacemakers are not reset on a regular basis, they will begin leading us toward a schedule further and further from what the world considers regular hours. In other words, within two weeks we could be eating breakfast at midnight and getting into bed at dawn.
If we look beyond superficial explanations to explore genuinely fundamental causes, irregularities in the internal biological clock stand revealed as one of the most significant causes of insomnia. It’s interesting to note that this loss of synchronization between the individual and his or her natural surroundings is a relatively recent phenomenon, at least in the degree to which we experience it today, and for this I blame two innovations that are fundamental to the benefits we enjoy in contemporary life, but which are definitely enemies of the natural sleep that our ancestors enjoyed.
These two innovations, which appeared in America at almost the same historical moment, are the electric light bulb and the notion of standardized time.
Time as we know it began only in the nineteenth century, after the Civil War. Until then, most regions determined their own time based on the position of the sun as they experienced it. Thus, “communities that were miles apart were also minutes apart.” This could lead to problems of interpretation and correspondingly confusing results.
For example, somehow, because of the way the sun appears to move across the sky from east to west, Sacramento, California, was more than three hours earlier than New York City—almost three thousand miles away—but Sacramento was also about four minutes later than nearby San Francisco. Railroads, like towns, operated according to different versions of the time, depending on the location of their hub cities, and train stations displayed a selection of clocks, one for each of the various companies.
It was the railroads, in fact, that finally brought about the change to standardized time. But the transformation didn’t come easily, for there was little public dissatisfaction with the multiple-time system. Today we completely accept the idea of one correct time that governs our lives: The time isn’t a matter of individual opinion or interpretation, it is supposed to exist somewhere, perhaps in Greenwich, England, and we can hear it repeated on the telephone or the radio. If you were to argue seriously about the time, you would undoubtedly be considered quite odd.
Yet it was only after ten years of meetings among railroad executives and assorted meteorologists that, on November 18, 1883, Standard Time went into effect with the dropping of a huge ball from the top of a building in New York City—a tradition that still continues on New Year’s Eve. Not everyone was glad to accept the new innovation. Certain states even refused to follow the new standard, but the Indianapolis Daily Sentinel expressed what eventually became the hard reality of the situation: “The sun is no longer to boss the job. People—55 million people—now eat, sleep, and work, as well as travel, by railroad time.”
Am I opposed to a system of standardized time? No, and it’s a little late for that anyway, by any reckoning. I want to live in the same world as everyone else. Later in this chapter you’ll learn how even the alarm clock, that anxiety-producing enforcer of the one true time, can be enlisted in the cause of better sleep. Yet in terms of reorienting us away from the natural rhythms of nature toward a man-made, machine-controlled, deterministic experience of external reality, the introduction of Standard Time is hugely significant.
From the would-be sleeper’s point of view, there’s very little to be said in favor of the electric light bulb.
After Edison’s development of the light bulb in 1879, darkness as it used to be known ceased to exist. The gas lighting that illuminated urban homes before that year, and the oil lamps that burned in rural areas, were effective to a certain degree, but they had disadvantages that made it easy for people to turn them off and go to bed. For instance, reading for long periods was difficult by gas or oil, and they were dirty compared with electricity. Also, compared with just flipping a switch, there was a certain amount of effort, sometimes even danger, involved in using gas or oil. (Rather than deal with them, the nineteenth-century poet Emily Dickinson preferred to compose many of her works in total darkness.) But with electricity there was almost nothing to it. By the turn of the century, you could stay up all night reading the standardized times of the train schedules.
The introduction of electric light in the home was another important factor in distancing us from the natural cycle of day and night. But, by comparison, the effect on our sleeping habits of electric lighting outside was much greater still. For one thing, electric lighting of the streets greatly increased the level of safety people could expect when they went out at night. And electricity ushered in modern forms of advertising, which provided all sorts of inducements for going out. Theaters, restaurants, and even amusement parks were fully illuminated, inside and out, within a few years of the invention of the electric light bulb. And at the Columbian Exposition in Chicago, in 1893, the wonder of electricity brightened literally miles of consumer goods in a vast department store created especially for the fair.
Throughout history, people had stayed home at night and, among other things, slept. They lived mostly in the country, and those who didn’t were too frightened of the poorly lit streets to take any chances. But by the beginning of the twentieth century, people were moving to the cities, and also moving further and further from the natural rhythm of light and dark, of sleeping and waking. They were certainly going out more, but they were probably sleeping less, and definitely sleeping worse.
Remember that in Ayurvedic terms, irregularity and changeability are qualities of Vata. The increasing divergence between our daily routines and the natural rhythms of life have been crucial in producing the sense of instability that arises from Vata imbalances. Today, this imbalance may be considered an epidemic.
There are enticing aspects of an irregular lifestyle that appeal to many people, but if the quality of your sleep has become a concern, you must learn to bring your body’s rhythm back into harmony with the natural cycles surrounding you. For above and beyond any man-made distractions, the rhythms of nature still exist and assert their force: The sun continues to rise and set, the tides ebb and flow, and these phenomena remain immensely powerful and influential, whether we recognize them or not.
The rest of this chapter is devoted to helping you reset your biological clock to its regular, orderly functioning in accord with all the cycles of nature. This is a key element in our approach to insomnia.
Scientists have observed many different influences on our physiology throughout the daily cycle. Your body temperature, your weight, your fluid balance, and the various thermostats throughout your body all undergo changes from minute to minute, from hour to hour. But Ayurveda says that there are master cycles in us governed by the quantum mechanical body and that each day we pass through these various cycles, which can be defined in terms of Vata, Pitta, and Kapha.
There are three cycles, each predominantly influenced by a different dosha, that take place from sunrise to sunset, and they repeat themselves from sunset to sunrise. The approximate times are as follows: From 6:00 to 10:00, A.M. or P.M., an influence of Kapha is dominant in the environment. From 10:00 to 2:00, A.M. or P.M., an influence of Pitta is more dominant. From 2:00 to 6:00, A.M. or P.M., an influence of Vata is dominant.
One of the most basic aspects of living in tune with nature is to respect these master cycles that support our physical existence. We are not meant to fight against nature’s waves; we are meant to ride with them, and our bodies experience a need to do that. It’s only when we interfere with the process that we experience discomfort, whether from insomnia or anything else.
Simply by looking around, you can see the obvious influence of these natural cycles. We don’t see birds awake at night except for owls, which have their own biological rhythm and their own purpose in nature’s scheme. When we look around in the evening we see that nature is resting. As the sun sets, everything is quiet and nature settles down. We ourselves feel comfortable sitting back and relaxing in the evening. Of course, if you live in a large metropolitan area you may wonder where this silence in the atmosphere is as you look out on the dynamic activity of evening. However, this activity is not the influence that is present in nature itself, but is a part of our modern lifestyle, which brings us into conflict with nature itself. Observing nature, we find a settling, a heaviness and silence in the environment during this Kapha period of day. If we allow it, this will be reflected in our bodies also, which will feel heavy and naturally prepared for sleep. If we are in tune with this natural rhythm and heed this urge for rest as part of our daily routine, it’s unlikely that insomnia will become a problem. But if we resist the desire for sleep, an entirely different pattern can begin to establish itself.
For this reason, 10:00 is a pivotal moment in the entire twenty-four-hour cycle. This is the junction point between the Kapha and Pitta periods of evening. Ayurveda recommends going to bed at or before this junction time, because then the mind and body will be under the influence of the Kapha dosha. If you remember the qualities of Kapha—dull, heavy, slow, stable—you will see that this influence in the environment is supportive of sleep.
What happens if you don’t go to bed by 10:00 P.M., when the influence of Pitta begins? By 10:30, this energizing influence has become quite lively in the environment. Remember that Pitta is an active dosha whose qualities are lightness, sharpness, and heat, which imply activity. And this influence will bring out activity in you.
Most people find that if they stay up until 10:30 or later, they can remain alert and mentally active until late into the night with no difficulty. A certain kind of exhilaration even begins to be felt. This is very clearly evident in children, who are so excited by the idea of “staying up late.” It also accounts for the fact that many creative people, whose art depends on the mental quickness and sharp juxtapositions of ideas, find it easiest to work at night. The great French novelist Honoré de Balzac was famous for sleeping all day, then waking up close to midnight to begin his work.
If you choose to stay up late, your sleep will be shallower and less rejuvenating, and even this sleep will be more difficult to achieve. Sleep researchers have established the fact that sleep becomes lighter as the night progresses. This is absolutely consistent with the Ayurvedic description of moving from Kapha to Pitta to Vata—from heaviest to lightest—during the course of the night.
An early bedtime is one of the most important points for bringing your system back into balance with nature, as it gives your body the ideal opportunity for deep rest and normal sleep. Once you’re in bed, adopt the nonminding attitude discussed in chapter 2. Above all, don’t worry so much about falling asleep that the worrying itself keeps you awake.
I had a patient who was seriously troubled by insomnia, and anxiety about it was only making the situation worse.
“I lie in bed every night until three-thirty in the morning,” he told me. “After that I’m able to fall asleep occasionally, if I’m lucky. But never before three-thirty in the morning.”
Fortunately, I was able to come up with a novel solution to his problem. “It seems like you’re worrying too much and trying too hard,” I suggested. “Just try to relax and do what comes easily to you. In other words, lie awake and don’t allow yourself to go to sleep before three-thirty in the morning. Look at the clock every once in a while in order to keep track of things, but don’t go to sleep before three-thirty.”
“But that’s what happens anyway,” he protested.
“Well, nothing else has worked,” I replied. “Just think of it as an experiment. You’ve been trying to do something that seems very difficult, which is going to sleep, so now give yourself the positive experience of doing something easy, which is staying awake.”
This idea had immediate success. My friend was asleep long before 3:30 A.M. When he removed the necessity for going to sleep and placing it instead on staying awake, the tension that had been present every night was defused, and sleep happened all by itself.
If you’re spending more time every night worrying about sleep than actually doing it, you might want to try the suggestion I offered to my patient. But I’m confident that for most people, an early bedtime and a nonminding attitude is the best approach. Of course, the very thought of this will make many people uncomfortable. Some may even react with a feeling of hopelessness or despair, as if you were asking the impossible. Others may say, perhaps even with some indignation, “I’m a night person, and I’ve always been one. I have more energy at night, and I have no desire at all to go to bed early.”
Of course, Ayurveda teaches that this is a misperception, that there is really no such thing as a night person. There’s only a person who may be out of synch with his or her natural biological rhythms. If you have insomnia, this is certainly one of the reasons for it. Over the years, many habits may have built up that help to reinforce not going to bed early. These may include late-night reading, radio talk shows, and television.
But the truth is that you’re paying a significant price for this nighttime activity, not only in the short term but also because of the diseases and imbalances that can arise as a result of deviating from your natural biological rhythms. After all, nature dictates that up to one-third or more of our lifetime is invested in sleep. We must demand the maximum return on that investment.
If you’ve become used to staying up past midnight, it’s perfectly reasonable for you to feel wide-eyed and full of energy and enthusiasm at that time. This is because long-established habits of staying up late have influenced your biological mechanisms in such a way that you do in fact experience peak energy and concentration at that time, even if it’s achieved at the cost of “sleepwalking” through the day. But if you’ll go along with my suggestion of early bedtime for a little while, you’ll realize that once you manage this change, your rhythms will fall into synchrony with universal rhythms, and any temporary disorientation you experienced will have been well worth the price.
You don’t have to make this transition overnight, so to speak, and it would be unwise to try, because you’ve been keeping late hours for a long time. But once your internal clock has been reset, I guarantee you’ll feel an amazing surge of energy in your daily experience—such buoyancy, such enthusiasm, such liveliness, such wakefulness, such creativity. You’ll enjoy so much more in life by being fully awake. Today many people are physically awake, but they’re not really awake; they’re not fully aware. They don’t have life-centered, present-moment awareness.
The French philosopher Montaigne wrote, “When I dance, I dance. When I eat, I eat.” It sounds so simple, but are you really there when you’re there, whether it’s a place or a moment in time? So much in the contemporary world undermines our ability to be truly in the present, which is a crucial element of enjoying life.
Insomnia, which so often is filled with regrets about the past and worries about the future, is in a sense the exact opposite of living life with a present-moment focus. Despite the “high” you may experience from living like a night owl, it’s no exaggeration to say that insomnia is something you must overcome before you can get the most out of every moment.
Many people suffer from what researchers call Delayed Sleep Phase Syndrome, which simply means that your internal biological clock has become mis-set over the years due to irregularities in your daily schedule, your diet, and other areas of your life.
As a result of this faulty internal clock, your system functions as if you were traveling from Los Angeles to New York on an airplane and were suddenly asked to go to bed at 10:00 P.M. New York time. Since your biological clock is set for three hours earlier, your body thinks it’s 7:00 P.M. and finds it very difficult to go to sleep. People who make this trip often end up going to bed at about 1:00 A.M. because they feel as if it is 10:00 P.M. Which is, of course, the common phenomenon of jet lag.
Some people, however, develop a similar disorder of their internal clock while at home. We’ve already seen how the introduction of electric light helped foster this, but that was only the beginning. In ancient days, people’s activities in their homes were very limited. Today, such activities are almost zmlimited, with so many new electronic devices coming along every year. And, whatever their benefits in entertainment or the accessing of information, all of these novelties are helping to produce individuals whose natural biological rhythms are further and further out of sequence with the rhythms of nature, especially the rhythms of dark and light, than was true of any generation in the past.
With everything we’ve discussed stacked against it, preparing for a proper bedtime may at first seem a thoroughly foreign activity. Here, then, are five specific recommendations for evening and pre-bed activities:
1. Supper should be light and should be eaten relatively early; between 5:30 and 7:00 P.M. is best, as a heavy or late supper will take a longer time to digest. Digestion involves increased metabolic activity, which works against settling down for sleep.
2. Take a short stroll after dinner, about five to fifteen minutes, to promote relaxation and to aid digestion.
3. Avoid exciting, dynamic, or focused activities in the evening. Try to keep this a settled, relaxed time. Many people find that they get wound up during the evening, then have trouble unwinding and falling asleep. If you must attend to some focused activity or work at night, stop by 9:00 P.M. at the latest. Don’t feel you’ve got to get everything done before you go to bed. If you have a good night’s sleep, you’ll have more energy, greater clarity, and greater success the next day.
4. Avoid watching TV in the evening. This may seem a tall order for many people, but it actually is very helpful for anyone who has a sleep disorder. If you must watch television at night, stop by 9:00 P.M. at the latest. TV, including programs that seem relaxing, is actually inherently exciting to the nervous system. It stimulates and even overstimulates sight, hearing, and overall mental function, and this aggravates Vata symptoms. Try substituting some light reading, listening to music, playing with children, having friends visit, or other relaxed activities.
5. Begin to prepare for bedtime at least thirty minutes before you intend to get into bed. Whatever routines you have before bed, such as brushing your teeth, as well as those you have added from this course, should be begun early enough to allow you to turn off the lights at your predetermined time. If you like to read before bed, do so in a room other than your bedroom. The bedroom should be associated with sleeping, not with mental activities such as reading or watching television.
These are some of the most important points in preparing for bed. But if, after reading them over, you still feel it’s impossible even to consider getting into bed by 10:00 P.M., simply begin to wake up earlier.
Ideally, of course, you should move up both your rising time and your bedtime gradually, by a few minutes every day, for a total of about fifteen to thirty minutes each week. Regardless of how you do it, however, one of the most important things you can do toward making your body want to go to sleep at 10:00 P.M. is to get up earlier. Even if you find yourself missing your bedtime, maintain the schedule faithfully with regard to your rising time by using an alarm clock. Continue until you have established a rising time between 6:00 and 7:00 A.M. If you’re diligent in this, the progressively earlier rising time will naturally lead to a progressively earlier bedtime, even though there may be some lag between the two.
This may seem a burden in the beginning, with the alarm clock and so on, but once you make a habit of waking at 6:00 or 7:00 A.M., your body will naturally want to go to sleep at 10:00 P.M. You won’t be able to resist it. A regular rising time is essential to anyone who wants to improve sleep patterns, because it sets the entire day’s activity off on a regular footing. It may take a few weeks on this schedule to achieve your goal, but gradually resetting your biological clock will lead you in the perfect direction for balancing Vata, and for making this change a permanent and beneficial one.
In general, there are two important points about the time you arise. First, you should wake at about the same time every day—preferably by 6:00 A.M. and certainly by 7:00 at the latest. Remember that Vata, which is irregular, is balanced by anything that is regular. Thus, regular arising is the most important thing you can do at the start of the day to balance the Vata dosha and improve your sleep patterns.
Second, you should set your time of arising so that it coincides with the end of the Vata period, at the junction point between the Vata and Kapha periods of morning. This means around sunrise, or about 6:00 A.M., when nature makes its transition from Vata to Kapha.
If you wake up prior to this transition, mind and body will still be under the influence of Vata qualities. Remember, these include alertness, lightness, activity, and quickness of mental and physical functioning. In addition, clinical studies have shown that rising early helps to alleviate depression. Awakening at this time prepares your mind and body for dynamic and effective functioning and clear mental activity during the day, which in turn sets the stage for sound sleep the following night.
If you sleep much beyond this time, you’ll be sleeping into the Kapha period of morning. Awakening then will imbue the mind and body with the Kapha qualities of heaviness, dullness, slowness, and sluggishness. You have probably experienced feeling dull and sluggish during the day after getting up late in the morning. Much of the fatigue you may have attributed to lack of sleep can actually be the result of falling asleep late in the night and then waking up very late in the morning, disrupting your biological rhythms altogether.
To sum up: I suggest that you have a fixed time for arising and that you adhere to it, even if you must use an alarm clock, as part of your program of resetting your biological clock. This applies to weekends and holidays as well.
In fact, one of the biggest aggravators of sleep problems is changing one’s wake-up pattern from workdays to weekends or holidays. That’s why Sunday night is often a very likely time for insomnia. You may have slept late over the weekend, and now the prospect of work, with its attendant anxieties, has reappeared—and since you aren’t tired due to sleeping late, you can’t get your eyes to close.
Once you set the alarm for a fixed rising time, get up then no matter how much or how little sleep you feel you’ve had or how tired you feel. Even if you have enjoyed little or no sleep, continue to follow your normal daytime work schedule. Studies show that even tasks that involve fine motor skills are not generally affected by sleep loss unless it continues for an extended period. So even if you feel mildly uncomfortable for a few days or even a week after beginning to wake up early, this will be more than made up for by the comfort you’ll derive from getting better sleep in the future.
When you get your daily rhythm back into line, you’ll begin to wake up spontaneously at the appropriate time, and you’ll be able to stop using the alarm clock. It’s interesting to realize that the process of awakening has plateaus, just as going to sleep does. The natural process of waking up doesn’t happen all at once. It certainly isn’t anything like getting jarred out of bed by an alarm. Instead, you begin to move away from sleep in three or four stages, drifting back and forth between waking consciousness and very light sleep a few times before you finally open your eyes.
This half-asleep state is a dangerous area for Vata dosha. If you start to awaken before six in the morning, when it’s still a Vata period, your thoughts might start racing and you’ll snap into a fully awake condition. If this happens too quickly, you won’t feel rested. You can feel tired for hours, as though you hadn’t slept at all during the night.
The process of awakening depends on specific biochemicals that need to enter your system gradually and in the proper sequence. If you snap awake like an electric light, or if it takes you too long to wake up, so that you feel heavy and groggy, you can be sure that your internal rhythm has not yet been stabilized.
Before we leave the area of daily routines, there is one more pivotal time I want to discuss: the lunch hour. This is the time to have the main meal of your day, because noon is the exact middle of the Pitta daytime period of 10:00 A.M. to 2:00 P.M. As we’ve seen, within the body, Pitta is responsible for metabolizing food, for distributing energy, and for more efficient physiological functioning in general. Pitta corresponds to the influence of the sun in nature, and it plays these same roles in the internal nature of an individual. So when the sun is at its peak around noon, there will be maximum support from the environment for the digestive processes in the body.
This means that if you take your lunch at this time of day, you can digest a larger quantity of food and assimilate it properly. This helps give maximum energy and avoids the need to take a large meal at bedtime, which would be more difficult to digest and would therefore not only interfere with sleep but contribute to the accumulation of impurities in the body.
For all these reasons, try to have your main meal at lunchtime, and if you’re in the habit of eating meat or other heavy foods, plan to make them part of lunch rather than dinner. Taken in the evening, these foods will sit in your stomach, and your body will strain to digest them when it should be settled and sleeping. Since work responsibilities can get in the way of having lunch on the job, making this the main meal of the day will definitely involve some extra planning. But with some creativity you can always find a way to accomplish this very important aspect of the daily routine.
You will definitely notice the benefits, not only in improved sleep but in increased energy, enhanced well-being, and better health in general.
The following are important points about the Ayurvedic daily routine and how it can help reset your biological clock so that sleep becomes that effortless and deeply restful experience that you remember so well from the past.
The ability to drift off into a restorative nap, even under trying conditions, is characteristic of some famous men of action. Churchill was known to nap every afternoon no matter what else was going on; John F. Kennedy was also a confirmed napper. In fact, during the height of the Cuban missile crisis in 1962, Kennedy refused to stay awake any longer after several days of working nonstop, and instead insisted on getting a full night’s sleep. This was surely a very wise decision.
If you feel tired during the day, it’s certainly healthier to take a nap than to drink a double espresso—indeed, the afternoon siesta is basic to daily routine in a large part of the world. If you like to take naps, however, there are several things to keep in mind.
First, be aware of the difference between deciding to take a nap and simply having sleep suddenly descend upon you whether you want it or not. If the latter situation occurs, particularly if it does so frequently, you may be suffering from one of the clinical sleep disorders discussed in this book. In Ayurveda, the notion of intention is a fundamental part of any action. If intention is not present, the benefits of napping (or anything else) are nullified.
Second, keep your naps under thirty minutes in length. If you sleep longer than that, you’ll enter the delta phase of deep sleep, from which awakening is most difficult. You’ll feel groggy and irritable and probably worse than before you fell asleep.
Finally, if you nap more than once a day, whether intentionally or not, you should have a medical evaluation. Such tiredness can be a symptom of conditions that are beyond the range of this book.