Polysomnography is a diagnostic test that is performed while you are completely asleep. A healthcare provider will observe you while you are sleeping, record data about your sleeping patterns, and identify any sleep disorders you may have.

During a polysomnography, the healthcare provider will measure the following to help chart your sleep cycles:

  • skeletal muscle activity
  • brain waves
  • heart rate
  • blood oxygen levels
  • eye movement
  • breathing rate

A sleep study registers shifts of your body as you go through different sleep cycles. These cycles are non-rapid eye movement (non-REM) sleep and rapid eye movement (REM) sleep. Non-REM sleep is further classified into “deep sleep” and “light sleep” phases.

Your brain activity is high during REM sleep. Only your breathing muscles and eyes are active. You also dream during this stage. On the other hand, during non-REM sleep, your brain activity is slower.

An individual who doesn’t have any sleep disorder shifts between REM and non-REM sleep and experiences multiple sleep cycles per night. Disruptions in your sleep patterns can be identified by observing your sleep cycles and reactions of your body to the changes in these cycles.

A polysomnography is used by a healthcare provider to diagnose sleep disorders. It often assesses the patient for symptoms of sleep apnea, a condition which is characterised by stoppage and restarting of breathing during sleep. Following are some of the symptoms of sleep apnea:

  • ongoing and loud snoring
  • sleepiness during the day despite having rested
  • frequent episodes of waking up during the night
  • periods of holding your breath during sleep, which are followed by gasps for air
  • restless sleep

The following sleep disorders can also be diagnosed by your doctor with the help of a polysomnography:

  • sleep-related seizure disorders
  • narcolepsy, which involves extreme drowsiness and “sleep attacks” during the day
  • Restless legs syndrome or periodic limb movement disorder, which involves uncontrolled extension and flexion of the legs while asleep
  • REM sleep behaviour disorder characterised by acting out dreams while asleep
  • chronic insomnia which is characterised by having difficulty falling asleep or remaining asleep

If left untreated, sleeping disorders can increase your risk of developing other medical conditions including high blood pressure, heart disease, depression, and stroke. There is an association between sleep disorders and increased risk of injuries related to car accidents and falling as well.

Before polysomnography, you should avoid consumption of caffeine and alcohol in the afternoon and evening of the day when the test is to be conducted. Caffeine and alcohol can affect sleep patterns and also certain sleep disorders. Your results can be impacted by having these chemicals in your body. You must also stop consuming sedatives.

You must share your medication history honestly with your healthcare provider so that he will guide you regarding whether or not you must stop taking those before the test.

A polysomnography is typically performed in a major hospital. Your appointment will generally start in the evening, around two hours before your usual bedtime. You will be directed to sleep overnight in the hospital, where you will be given a private room or chamber. You will be free to bring along your necessary stuff that you need for your bedtime routine.

The polysomnography procedure will be administered by a technician who will monitor you while you are asleep. You will be able to talk with and hear the technician during the night as he can see and hear inside your room.

During the polysomnography, the technician will measure your:

  • eye movements
  • brain waves
  • skeletal muscle activity
  • blood pressure
  • heart rate and rhythm
  • breathing patterns, including absence or pauses
  • blood oxygen level
  • limb movement
  • body position
  • snoring and other noises

To record this data, the technician will place electrodes (small sensors) on your temples, scalp, chest, and legs. The sensors come with adhesive patches so that they stay on your skin while you sleep.

Your breathing patterns and chest movements will be recorded by elastic belts tied around your chest and stomach. Your blood oxygen levels will be monitored by a small clip on your finger. The sensors are connected to thin, flexible wires that send your data to a computer. The technician even sets up equipment to make a video recording for future reference in some special cases.

This helps you and your healthcare provider to review the changes in your body position during the night. You might not feel as comfortable sleeping at the hospital as you feel being at home in your own bed. So, you may not fall asleep or stay asleep as nicely as you would at home. This doesn’t usually alter the data thankfully as normally a full night’s sleep is not required to produce accurate polysomnography results.

The technician will remove the sensors when you wake up in the morning. You can leave the hospital and resume your normal activities of daily life on the same day.

Polysomnography is a noninvasive and painless procedure that is usually free from any risks. You may experience a mild skin irritation

The results of your polysomnography take upto three weeks to be ready. The data will be compiled by a technician from the night of your sleep study so that your sleep cycles can be graphed. The concerned doctor will then review this data, your sleep history, and overall medical history to establish a diagnosis.

If the results of your polysomnography are not normal, it may point towards one of the following sleep-related disorders:

  • seizure disorders
  • sleep apnea or other breathing disorders
  • narcolepsy or other sources of unusual daytime fatigue
  • periodic limb movement disorder or other movement disorders

To identify sleep apnea, your healthcare provider will review the results of the polysomnography to look for:

  • the frequency of apnea episodes, which happen when breathing stops for more than 20 seconds
  • the frequency of hypopnea episodes, which happen when there is partial blockage of breathing for at least ten seconds
  • With this data, your healthcare provider can measure your results with the apnea-hypopnea index (AHI). An AHI score less than five is considered to be normal

This score, along with the muscle movement data and normal brain wave data generally indicates that you don’t have sleep apnea.

If you have an apnea-hypopnea index score of five or more, it is considered to be abnormal. In such a case, the healthcare provider will chart the abnormal results to determine the degree of sleep apnea:

  • An AHI score greater than 30 indicates severe sleep apnea.
  • An AHI score of 15 to 30 indicates moderate sleep apnea.
  • An AHI score of 5 to 15 indicates mild sleep apnea.

If you receive a diagnosis of sleep apnea, your doctor may recommend a device called continuous positive airway pressure (CPAP) machine for your use. With this machine, you can get a constant air supply while you are asleep. The right CPAP setting for you can be determined by a follow-up polysomnography.

Consult specialists to understand all the options available for treatment of sleep disorders.

Warning signs of sleeping disorders

The following may be warning signs of a sleep disorder:

  • perpetual irritability and fatigue during the day, even after getting seven or eight hours of sleep a night
  • consistently taking more than 30 minutes to fall asleep
  • frequent and long naps during the day
  • waking up several times in the middle of the night and remaining awake, sometimes for hours
  • falling asleep at inappropriate times, mostly when sitting still while watching television or reading
  • difficulty concentrating at work or school
  • waking up too early in the morning
  • loud breathing, snoring, or gasping noises while you sleep
  • crawling feeling in the legs, particularly at bedtime
  • an irresistible urge to move your legs, or a tingling or requiring a stimulant like caffeine to keep you awake during the day

Possible causes of sleep disorders

A sleep disorder sometimes occurs secondary to a medical condition. Some medical conditions that have been linked with sleep disorders include asthma, nasal and sinus inflammation, high blood pressure, diabetes mellitus, anxiety, Parkinson’s disease, and clinical depression.

Sometimes, a sleep disorder is also caused by nonmedical factors including lifestyle factors, poor sleeping habits, dietary choices, and stressful circumstances. Paying close attention to agents that could be causing your sleeping problems is important.

Types of sleep disorders

Many people are affected by sleep disorders. You should not be hesitant to discuss your problem with your doctor if you think you might be suffering from one.


Insomnia is defined as the failure to fall asleep or stay asleep, resulting in functional impairment throughout the day. It is one of the most commonly diagnosed sleep disorders. The duration of sleep varies to a great extent depending on the employment status, profession, state of residence, and marital status. Having chronic medical conditions like heart disease or diabetes may also increase your risk of developing insomnia.

Restless legs syndrome (RLS)

Restless leg syndrome is an unpleasant creeping sensation that can result in pains and aches in the legs, making it challenging for you to fall asleep. Most patients with restless leg syndrome are middle aged or older. Females are twice as likely to suffer from the condition compared to males.

Restless leg syndrome is classified as a neurological condition and its diagnostic methods and treatment options are different from other sleep disorders. If you think you are experiencing symptoms of restless leg syndrome, you should talk to a doctor so that he can help you find relief from both the symptoms of the syndrome and its underlying cause.

Sleep apnea

Sleep apnea can be defined as uninterrupted sleep that occurs due to snorting noises or periodic gasping, or the temporary suspension of breathing. Polyps in the sinuses or deviated septum can cause breathing difficulties while you are asleep. Patients with sleep apnea fail to get enough oxygen while they are sleeping. This results in sleep interruption and disturbance.

The treatment of sleep apnea is usually done with a small machine and a mask that exerts pressure on the sinuses while sleeping. This treatment is known as continuous positive airway pressure (CPAP). Surgery and some oral appliances may also be recommended as treatment options for sleep apnea.

A study has shown that those who have post-traumatic stress disorder are around 70 per cent more susceptible to developing sleep apnea. Obesity also increases the chances of developing sleep apnea.

Other sleep disorders

Following are some less common sleep disorders:

  • Narcolepsy
    It is a condition in which a person cannot control when they fall asleep. So, they have episodes of unwanted sleep.
  • Circadian rhythm sleep disorder
    It is characterised by trouble a person has to align their body’s natural inclinations for sleep with the sun set and sunrise.
  • Kleine-Levin syndrome or “Sleeping Beauty” syndrome
    It is a condition characterised by long periods of sleep in a person, for two or more days at a time
  • Idiopathic hypersomnia
    In this condition, the person is uncontrollable sleepy or tired in spite of getting the recommended amount of sleep consistently.

Treatments for sleep disorders

The treatment of sleep disorders depends on the underlying cause. Many treatment options are available for these disorders— ranging from prescription medications to behavioural therapies.

Relaxation techniques including deep breathing and meditation, are usually the first treatment recommended by healthcare providers when a person is diagnosed with insomnia. Some prescription medications are also available to treat sleeping disorders. These medications help you fall asleep more effortlessly and you can sleep for longer durations of time. Sometimes, these medications give rise to dependence, so you should take those only on recommendation of a registered doctor.

A diverse range of factors, both non medical and medical, influence a healthy sleep. So, it is essential to practise good sleep hygiene for greater productivity and happiness. You must play close attention to your sleep habits, and don’t shrug off your exhaustion as something you simply have to live with. You will find relief for sleepless nights through healthy habits and medical treatment. Adequate amount of good quality sleep is important for good physical and mental health. So, don’t take this aspect of your health lightly.

The Department of Pulmonary Medicine at Kokilaben Dhirubhai Ambani Hospital, Indore offers comprehensive diagnostic and therapeutic care for a diverse range of sleep disorder. Our staff comprises highly qualified pulmonologists who deliver optimum treatment for lung diseases supported by state-of-the-art technology and modern equipment. We are equipped with the most advanced polysomnography test in Indore. Reach out to the best sleep experts in Indore at our hospital.

We follow an evidence-based approach during all our services to ensure excellent outcomes matching international standards. Apart from having a fully-equipped Bronchoscopy suite with C-arm facilities, we house a state-of-the-art PFT machine. Our focus is on ensuring the speedy recovery of the patient and helping him return to normal activities of daily life as soon as possible.