Each week, MyHealthNewsDaily asks the experts to answer questions about your health.

This week, we asked internal medicine physicians and sleep experts: Is having trouble sleeping -- and the resulting lack of sleep -- bad for your health? Here's what they said.

Dr. William Kohler, medical director of the Florida Sleep Institute:

"Sleep is necessary for us to function at our best, and if we do not get adequate quantity and quality of sleep, our performance and our functioning is not going to be satisfactory. If we don't get adequate sleep, our mood is going to be more depressed, we're not going to be as sharp cognitively, our thinking is not going to be as alert. And with lack of sleep, there are long-term potential consequences and changes in our health: Our immune system is not going to function as well if we do not get adequate sleep, and we're going to have a tendency to put on weight. There are some fascinating studies that they've done with children where they follow children for a number of years, and ones with short sleep times were more likely to become obese than children who had adequate sleep.

"There are various sleep problems that have significant health morbidity associated with them, like sleep apnea. Apnea is stoppage of air flow for more than 10 seconds at a time, and significant apnea can lead to heart attack, stroke, high blood pressure, irritability, depression, elevated cholesterol and elevated blood sugar. It's also bad because it causes one to wake up a lot, and decreases the quantity and quality of sleep. You're not getting enough hours [of sleep] if you're tossing and turning and you're arousing frequently, so the quality of sleep and the restoration isn't going to be there."

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Dr. Sheila Tsai, sleep expert and assistant professor of medicine at National Jewish Health in Colorado:

"The short answer is yes. Studies have looked at the effects of sleep duration on health. In those people who do not get enough sleep per night (generally less than six hours per night), there is an increased risk of cardiovascular disease and death versus people who do get enough sleep. In people suffering from insomnia, with problems falling asleep and/or staying asleep, an increased risk for major depression has been noted. In addition, insomniacs have increased work errors, loss of productivity, and days absent from work due to their sleep issues.

"'Trouble sleeping' may also be a sign of another sleep disorder such as obstructive sleep apnea (OSA), in which the airway closes or collapses at night, leading to oxygen desaturations and fragmented sleep. The poor sleep quality in OSA results in sleepiness. People with OSA have an approximately sevenfold increased risk for motor vehicle accidents. Other health consequences of OSA include problems with blood sugar control, obesity, increased cardiovascular problems such as hypertension and increased incidence of mood disorders. Therefore, it is important to address your sleep problems with your medical provider because good sleep is vital to good health."

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Dr. Madeleine Grigg-Damberger, associate medical director of the University of New Mexico Clinical Neurophysiology Laboratory and director of Pediatric Sleep Medicine Services at the University Hospital Sleep Disorders Center:

"Insufficient sleep, or short sleep, can contribute to weight gain. It can change the balance of your nervous system, favoring sympathetic activity, like fear and fright. Usually, sleep is a vagal parasympathetic moment: Frequent arousals and sleep deprivation, just like starvation, wires up the nervous system toward adrenaline, survival mode. It's bad on your heart. Sleep deprivation changes the glucose metabolism so that because you're stressed, there's an adrenaline response. The adrenaline response affects cortisol metabolism -- so as a result, you change to an insulin resistant diabetic model.

"Insufficient sleep -- be it due to fragmented sleep from some underlying sleep disorder, or worry or stress, or frequent apneas arousing you from sleep -- contribute to hypertension, loss or dipping of blood pressure, insulin resistance, overweight and sudden death. But the amount of sleep people need varies from four to 11 hours per day, though most people need seven-and-a-half to eight hours of sleep per night. Most Americans are too often getting six-and-a-half hours and it's not good for them.

"Older people have more fragmented sleep perhaps because they nap a bit more during the day. And studies show they're more resistant to the effects of sleep deprivation than younger people, or they're not seeing differences as much. But just like young people, elders who sleep nine hours a day or sleep four or five hours a day, those two ends of the spectrum, may be a problem."

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Dr. Kristen Gill Hairston, assistant professor of endocrinology and metabolism at the Maya Angelou Center for Health Equity and Center for Diabetes Research at Wake Forest Baptist Medical Center in North Carolina:

"Extremes of sleep -- both too much and too little -- can be hazardous to your health, especially for young minority women, a group most affected by obesity and chronic metabolic disease. There's more to 'fat' than what we choose to eat -- getting less than six hours or more than eight hours [of sleep]could be causing dangerous fat deposition around vital organs.

"We put a lot of stock in diet, but research brought up some interesting questions about the way we live. We may need to start looking at other behaviors besides daily food choices that could be contributing to the obesity epidemic in younger age groups.

"We definitely know that a relationship exists between sleep and obesity, but now we need to know how this relationship can be modified. It will be important for future obesity research to consider sleep patterns and the effect they can have on outcomes. Until the connection is understood, physicians should consider gathering information about sleep patterns just as they do other vital information when seeing patients. This information is especially relevant when treating patients about to make or in the middle-of-life transitions, such as college, marriage and childbearing, because such times are often associated with sleep deprivation in younger years. This information may help a physician put into context other issues going on in the patient's life which may be affecting their overall health."

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Dr. Wallace E. Johnson, director of the Center for Primary Care at the University of Rochester Medical Center:

"The consequences of sleep deprivation are being increasingly recognized. These problems range from car crashes and workplace errors to immune dysfunction. Insufficient or poor quality sleep has been linked to heart problems and to obesity.

"Many people suffer short bouts of insomnia at some point in their lives, but insomnia can also be a symptom of an underlying physical or psychological disorder. It is important to talk to your doctor about your insomnia problems in the context of your overall physical and psychological health. Sleep-inducing medications alone, either over-the-counter or by prescription, are seldom good solutions long-term.

"There are two main forms of insomnia: 'Initial insomnia' means trouble falling asleep, while 'early morning awakening' is characterized by a middle-of-the-night arousal and rumination. Initial insomnia is common in older people and can often be overcome by 'good sleep hygiene': Avoid reading or eating or watching TV in bed. You want your mind to keep the 'bed equals sleep' connection. Early morning awakening is often a manifestation of underlying anxiety or depression.

"Don't be embarrassed about talking to your doctor about your sleep problems. You'll be glad you did, as a good night's sleep is great preventative medicine."

Pass it on: Trouble sleeping can lead to weight gain, anxiety, depression, weight gain and immune dysfunction. Sleep apnea, which can cause trouble sleeping, is dangerous and should be treated by a doctor.

Follow MyHealthNewsDaily staff writer Amanda Chan on Twitter @AmandaLChan.