Department of Sleep Diagnostics

Sleep Apnea

More than 18 million Americans suffer from Sleep Apnea and 10 million Americans remain undiagnosed.

Could your Snoring Mean Something More?

If you snore, you may know about nightly jabs in the ribs, grumbling from your bed partner or even what it’s like to spend a night or two on the couch! But did you know that snoring could signify something far more serious than a restless night’s sleep for the others in your household? You may have an unsafe condition called Sleep Apnea.

Sleep Apnea is Serious

Obstructive Sleep Apnea (OSA) sleepA common sleep disorder is Obstructive Sleep Apnea, which is when a person stops breathing repeatedly during sleep. Sleep Apnea is a serious, potentially life-threatening condition. When a person goes to sleep, the muscles that stiffen and open the throat will relax, leading to a slight sleep-related narrowing of the throat that can cause either partial or complete obstruction.

For a person with Obstructive Sleep Apnea, this narrowing of the throat is so great that breathing becomes very difficult, or the throat may close off completely. The person’s brain senses this and makes an increased effort to breathe. This increased effort briefly awakens the brain in order to open the throat, and the person is able to breathe again with less effort and resumes sleeping. As soon as the person resumes sleeping, the throat will close off again, and the cycle begins anew. This can occur dozens to hundreds of times each night!

A person with Obstructive Sleep Apnea may not get a restful sleep or enough oxygen during sleep. This can lead to daytime sleepiness that affects work, social activities, and family life. Sleep Apnea can also increase a person’s risk of high blood pressure, heart failure, heart attack, or stroke.

There are many warning signs and symptoms of OSA. These include:

  • Snoring, interrupted by pauses in breathing
  • Gasping or choking during sleep
  • Excessive leg movements
  • Restless sleep
  • Excessive sleepiness or fatigue during the day
  • Waking up tired, even after a full night’s sleep
  • Falling asleep at inappropriate times
  • Problems with concentration or memory
  • Having a short temper
  • Waking up with morning headaches
  • Obesity
  • Depression
  • High Blood Pressure
  • Irritability
  • Impotence
  • Bed wetting

If untreated, Sleep Apnea can cause:

  • Irregular heartbeat
  • High blood pressure
  • Enlargement of the heart
  • Increased risk of heart failure
  • Increased risk of stroke
  • Excessive sleepiness
  • Workplace and automobile accidents
  • Impotence
  • Uncontrollable weight gain
  • Psychological symptoms (i.e. irritability, depression)
  • Deterioration of memory, alertness and coordination
  • Death

Other Sleep Disorders

Periodic Limb Movement Disorder (PLMD) A sleeping disorder that affects the limbs as well as a person’s ability to sleep at night and function normally during the day is called Periodic Limb Movement Disorder (PLMD). Most people with this disorder are not aware of these movements.

Restless Legs Syndrome (RLS) People who experience Restless Legs Syndrome often describe a very unpleasant “crawly, creepy” sensation that occurs in the legs (or sometimes the arms) when they are sitting or lying still, especially at bedtime. This sensation most often appears in the calves of the legs, and it is temporarily relieved by stretching and moving the legs.

Insomnia Insomnia can be defined as a sleeping disorder in which a person has trouble falling asleep or staying asleep. One out of three American adults suffer from Insomnia. This sleeping disorder disturbs a person’s sleeping and waking hours, leading to daytime sleepiness and an inability to focus on daily tasks.

Narcolepsy Narcolepsy can be defined as constant sleepiness and a tendency to sleep at inappropriate times. This disorder affects 1 in 2,000 people and has a significant, sometimes even disabling, impact on a person’s life. A person with Narcolepsy generally suffers “sleep attacks” as well as continued sleepiness that isn’t relieved by any amount of sleep. If it isn’t recognized and managed appropriately, this disorder can drastically affect a person’s life.

Parasomnias Parasomnia refers to a wide range of disruptive sleep-related events such as sleepwalking, confusion arousals, and sleep terrors. These events most often occur during sleep, and are usually infrequent and mild. However, in some people these events occur often enough and are so severe that they need medical attention.

Sleep and Heart Disease Sleep-related breathing disorders have been shown to play a major role in causing several types of heart disease. Although all aspects of the relationship are not clear, there is a definite connection between sleep disorders and heart disease. Various studies have linked sleep-related breathing disorders with increased rates of high blood-pressure, increased risk of heart disease, and stroke.

Sleep and Depression In some cases, sleep problems may be related to a condition called depression. Depression is viewed as a disease that involves how we feel about ourselves and how our body functions. However, just because a person doesn’t sleep at night doesn’t mean he/she has depression. Depression is only one cause of difficulty sleeping. If a person’s sleep problems are related to depression, the key to improving sleep is treating the depression first.

Sleep and Health Sleeping well is the first step to living well. This is why eliminating or reducing sleep problems is so important to a person’s health and well being. If a person has trouble sleeping, or if he/she feels tired and sleepy much of the time, then that person may have a sleep disorder. There are treatments for most sleep disorders, but the first step is to recognize that there is a problem. The second step is finding the cause of the problem, and the third step is treating the problem.


Sudhir Sehgal, MD

Diplomate, American Board of Sleep Medicine 116 Medical Park Lane, Suite B Huntsville, Texas 77340. Office Phone 936-439-4835 Office Fax 936-439-4837


1990-1996 M.B.B.S, Seth G.S Medical College at King Edward Memorial Hospital. Bombay, India


January 2009- Present Full time Consulting Physician in Pulmonary, Critical Care and Sleep Medicine at Huntsville Memorial Hospital in Huntsville,Texas July 2003-December 2008 Full time Consulting Physician in Pulmonary, Critical Care and Sleep Medicine at Covenant Medical Center in Waterloo, Iowa. 2000-2003 Fellowship in Pulmonary and Critical Care, Baylor College of Medicine-Houston 1997-2000 Internal Medicine Residency, Cook County Hospital-Chicago 1996-1997 Radiology House Staff Officer, King Edward Memorial Hospital-Bombay Performed and read conventional radiology, and ultrasound, including ob ultrasounds, and interventional ultrasounds. 1995-1996 Rotating Internship, King Edward Memorial Hospital


Currently Director- Huntsville Sleep Center, Huntsville, TX Currently Director -ICU at Huntsville Memorial Hospital, Huntsville, TX Previously Chairman -Department of Medicine at Covenant Medical Center, Waterloo, IA Previously Director – ICU at Covenant Medical Center, Waterloo, IA Previously member of the Steering committee for Electronic Health Records at Covenant Medical Center, Waterloo, IA

Licensure and Certifications:

Permanent Texas Permanent licensure from the Medical Council of India Board Certified in Internal Medicine Board Certified in Pulmonary Medicine Board Certified in Sleep Medicine Board Certified in Critical Care Medicine Certified and well experienced in Basic and Advanced Life Support (American Health Association.)

Professional Organizations

Active member of:

  • American Thoracic Society
  • American College Chest Physicians
  • American Academy of Sleep Medicine
References available upon request.


When you sleep, your body rests and restores its energy levels. However, sleep is an active state that affects both your physical and mental well-being. A good night’s sleep is often the best way to help you cope with stress, solve problems, or recover from illness.

What Happens During Sleep?

Sleep is prompted by natural cycles of activity in the brain and consists of two basic states: rapid eye movement (REM) sleep and non-rapid eye movement (NREM) sleep, which consists of Stages 1 through 4. During sleep, the body cycles between non-REM and REM sleep. Typically, people begin the sleep cycle with a period of non-REM sleep followed by a very short period of REM sleep. Dreams generally occur in the REM stage of sleep.

What Is Non-REM Sleep?

The period of NREM sleep is made up of stages 1-4. Each stage can last from 5 to 15 minutes. A completed cycle of sleep consists of a progression from stages 1-4 before REM sleep is attained, then the cycle starts over again.

  • Stage 1: Polysomnography {sleep readings) shows a reduction in activity between wakefulness and stage 1 sleep. The eyes are closed during Stage I sleep. One can be awakened without difficulty, however, if aroused from this stage of sleep, a person may feel as if he or she has not slept. Stage 1 may last for 5 to 10 minutes. Many may notice the feeling of falling during this stage of sleep, which may cause a sudden muscle contraction (called hypnic myoclonia).
  • Stage 2: This is a period of light sleep during which polysomnographic readings show intermittent peaks and valleys, or positive and negative waves. These waves indicate spontaneous periods of muscle tone mixed with periods of muscle relaxation. The heart rate slows and the body temperature decreases. At this point, the body prepares to enter deep sleep.
  • Stages 3 and 4: These are deep sleep stages, with stage 4 being more intense than Stage 3. These stages are known as slow-wave, or delta, sleep. If aroused from sleep during these stages, a person may feel disoriented for a few minutes.

During the deep stages of NREM sleep, the body repairs and regenerates tissues, builds bone and muscle, and appears to strengthen the immune system. As you get older, you sleep more lightly and get less deep sleep. Aging is also associated with shorter time spans of sleep, although studies show the amount of sleep needed doesn’t appear to diminish with age.

What Is REM Sleep?

Usually, REM sleep occurs 90 minutes after sleep onset .The first period of REM typically lasts 10 minutes, with each recurring REM stage lengthening, and the final one may last up to an hour. Polysomnograms show brainwave patterns in REM to be similar to that recorded during wakefulness. In people without sleep disorders, heart rate and respiration speed up and become erratic during REM sleep. During this stage the eyes move rapidly in different directions. Intense dreaming occurs during REM sleep as a result of heightened brain activity, but paralysis occurs simultaneously in the major voluntary muscle groups. REM is a mixture of encephalic (brain) states of excitement and muscular immobility. For this reason, it is sometimes called paradoxical sleep. The percentage of REM sleep is highest during infancy and early childhood. During adolescence and young adulthood, the percentage of REM sleep declines. Infants can spend up to 50% of their sleep in the REM stage of sleep, whereas adults spend only about 20% in REM.

How Much Sleep Do You Need?

The amount of sleep a person needs depends on the individual. The need for sleep depends on various factors, one of which is age. Infants usually require about 16-18 hours of sleep per day, while teenagers need about 9 hours per day on average. Most adults need about 7-8 hours of sleep per day. The amount of sleep a person needs also increases if he or she has been deprived of sleep. People do not seem to adapt to getting less sleep than they need.

What Are the Consequences of Too Little Sleep?

Too little sleep may cause:

  • Impaired memory and thought processes
  • Depression
  • Decreased immune response

Sleep deprivation also magnifies alcohols effects on the body, so a fatigued person who drinks will become much more impaired than someone who is well-rested. Caffeine and other stimulants can temporarily overcome the effects of severe sleep deprivation, but cannot do so for extended periods of time.

Accredited Logo-JAspire Hospital Sleep Center is accredited by the American Academy of Sleep Medicine (AASM) to perform all of the following tests. In addition, our sleep center tries to accommodate shift workers, whose schedules are opposite the general public, by offering studies during the day that are usually performed overnight. All of the tests performed are non-invasive.


Diagnostic Polysomnography (PSG): The PSG is an overnight study used to diagnosepatients with Obstructive Sleep Apnea.A sleep study, also called a polysomnogram (PSG), measures your brainwave activity, eye movements, muscle contractions, heart activity, breathing and blood oxygenation during sleep.

CPAP/BiPAP Titration: A Titration study uses the same monitors as a polysomnography but, in addition, a titration mask is applied to the patient. During the study, the Continuous Positive Airway Pressure is adjusted to find the treatment level that eliminates your sleep apnea.

Split Night: This test is part Diagnostic study and part Titration study performed during one testing period.

Multiple Sleep Latency Test (MSLT): These are day studies used when the patient is negative for sleep apnea but still has daytime sleepiness or suspected Narcolepsy. The MSLT consists of multiple nap opportunities with breaks lasting for two hours between them. The first nap trial begins between 1-1/2 to 3 hours after the patient wakes up from the overnight sleep study.

Maintenance of Wakefulness (MWT): This sleep study is frequently required for people who work in transportation or safety-related occupations (truck drivers, pilots, school bus drivers, etc.). The MWT is a diagnostic tool that measures your ability to stay awake.

Home Sleep Testing: On some occasions a patient may qualify for a Home Sleep Test. This test captures some of the same information obtained in the lab, but is performed in your home. Patients must qualify for this test, and not all insurances cover it.

Frequently Asked Questions:

Q. What is a polysomnogram?

A. A polysomnogram is a comprehensive recording of biophysical changes that occur during sleep, including:

  • Brain activity – electrodes attached to the scalp
  • Heart rhythm- electrodes attached to chest and abdominal region
  • Eye movements- electrodes attached near the eyes
  • Muscle activity — electrodes attached to the chin and lower legs
  • Snore sensor- placed on the neck
  • Respiratory effort – elastic belts placed around the chest and abdomen
  • Nasal/oral airflow — probes placed between the upper lip and nose
  • Oxygen saturation — sensor attached to the finger

Q. Why do a polysomnogram?

A. To look for behavior that can be harmful to yourself or others. Disrupted sleep can disturb daytime activities such as driving and can cause or complicate medical problems which affect basic health, for example diabetes and congestive heart failure.

Q. How can I sleep with all those sensors on me?

A. Most people sleep very well. The sensors are applied so that you can turn and move during sleep. The wires are ponytailed together so that entangling does not occur. If a sensor comes off during the study, your technician will come in the room and reattach the sensor. We ask that you move a little more gingerly, but you can sleep in your normal position. If you feel that you will have any problem with anxiety or falling asleep at our facility, you can contact your physician to see if a sleep aid can be prescribed for you. Unfortunately, we are not able to dispense or provide a sleep aid for you

Q. Will the sensors hurt?

A. No. The electrodes are placed on the skin to record information, but the recording is non-invasive and is not painful.

Q. Am I able to use the restroom during the test?

A. Yes. Prior to the beginning of the study the technician will ask you to use the restroom. During the night if you wake and need to use the restroom, you can notify your technician by intercom that you need a restroom break. Your technician will disconnect the main cable that will allow you to carry your electrodes to the restroom. A bedside commode or urinal can be provided if necessary. Please let your technician know if you need one of these items.

Q. Will I need a caregiver?

A. If you require any assistance at home, you will need a caregiver to stay with you on the night of your study. The technicians are not registered nurses or certified caregivers; they are there for the collection of data and to administer CPAP therapy, if required. If you are unable to speak English, deaf, or cannot communicate your wishes, you will need to bring someone who can interpret for you. (If you are unable to move by yourself less than thirty feet, sit up in bed without aid, and control bodily functions, you will need a caregiver to stay with you for the entire length of the study.)

Q. Is the test covered by my insurance?

A. The sleep test is covered by most insurance companies including Medicare.

Q. What happens after my study?

A. The results are reviewed by a sleep scoring technologist and then verified by a physician that is board certified in sleep medicine. Once the sleep center receives the report from the sleep specialist physician, we will forward a copy to your referring physician. Please allow several days for the report to be sent to your referring physician.

Department of Sleep Diagnostics 122 Suite B, Medical Park Lane, Huntsville, Texas 77340. Phone: 936-293-8883 Fax: 936-293-8773  

Aspire Hospital - Department of Sleep Diagnostics

Aspire Hospital - Department of Sleep Diagnostics
122 Medical Park Lane, Suite B; Huntsville, TX 77340
Phone: 936-293-8883 Fax: 936-293-8773