What is Polysomnography? Purpose, Procedure & Results

Polysomnography is a comprehensive sleep study that monitors your brain waves, breathing, and body movements while you sleep. Think of it as a detailed overnight recording that helps doctors understand what's happening in your body during sleep. This painless test takes place in a comfortable, hotel-like sleep lab where trained technicians monitor you throughout the night.

What is polysomnography?

Polysomnography is the gold standard test for diagnosing sleep disorders. During this overnight study, multiple sensors are gently attached to your body to record various biological signals while you sleep naturally. The test tracks everything from your brain activity and eye movements to your heart rate and muscle tension.

The word "polysomnography" literally means "many sleep recordings." Each sensor provides a different piece of the puzzle, helping your doctor see the complete picture of your sleep patterns. The test is completely non-invasive and doesn't require any needles or uncomfortable procedures.

Most people find the experience surprisingly comfortable once they settle in. The sleep lab rooms are designed to feel like a nice hotel room, with comfortable beds and dim lighting to help you relax.

Why is polysomnography done?

Your doctor might recommend a sleep study if you're experiencing symptoms that suggest a sleep disorder. The most common reason is suspected sleep apnea, where your breathing stops and starts during sleep. This test can also diagnose other conditions like restless leg syndrome, narcolepsy, or unusual sleep behaviors.

Sleep studies help doctors understand why you might be feeling tired during the day despite spending enough time in bed. Sometimes the quality of your sleep is poor even when the quantity seems adequate. The test reveals disruptions you might not even be aware of during the night.

Your healthcare provider might also order this test if you have loud snoring, gasping during sleep, or if your partner notices you stop breathing at night. These symptoms can indicate serious sleep disorders that affect your overall health and wellbeing.

What is the procedure for polysomnography?

The sleep study begins in the early evening when you arrive at the sleep center. You'll be shown to your private room, which looks similar to a comfortable hotel room with a regular bed, television, and bathroom. The technician will explain the entire process and answer any questions you might have.

Next, the technician will attach various sensors to your body using medical adhesive that's gentle on your skin. These sensors will monitor different aspects of your sleep throughout the night. The attachment process takes about 30 to 45 minutes, and while it might feel unusual at first, most people adapt quickly.

Here's what gets monitored during your sleep study:

• Brain waves through electrodes placed on your scalp
• Eye movements with sensors near your eyes
• Muscle activity using electrodes on your chin and legs
• Heart rhythm through chest electrodes
• Breathing patterns with belts around your chest and abdomen
• Oxygen levels using a small sensor on your finger
• Air flow through sensors near your nose and mouth

Once all sensors are in place, you can relax, watch TV, or read until your normal bedtime. The technician monitors you from a separate room throughout the night, so you'll have privacy while still being safely observed.

In the morning, the technician will remove all the sensors and you'll be free to go home. The entire experience typically lasts from about 8 PM to 6 AM, though exact times can vary based on your sleep schedule and the lab's protocols.

How to prepare for your polysomnography?

Preparing for your sleep study is straightforward, but following a few simple steps can help ensure the best results. Your goal is to arrive at the lab ready to sleep as naturally as possible. Most sleep centers will provide you with detailed instructions when you schedule your appointment.

On the day of your study, try to maintain your normal routine as much as possible. Avoid napping during the day, as this can make it harder to fall asleep at night in the unfamiliar environment. If you normally exercise, light activity is fine, but avoid intense workouts close to bedtime.

Here are some important preparation steps to follow:

• Wash your hair with regular shampoo and avoid using conditioner, oils, or styling products
• Remove nail polish from at least one finger for the oxygen sensor
• Bring comfortable pajamas or sleepwear
• Pack your regular medications and take them as prescribed
• Avoid caffeine after 2 PM on the day of your study
• Don't drink alcohol on the day of your test
• Bring any items that help you sleep, like a favorite pillow or book

Let your doctor know about all medications you're taking, including over-the-counter sleep aids. Some medications can affect your sleep patterns and test results. Your healthcare provider will advise whether you should continue or temporarily stop any medications before the study.

How to read your polysomnography results?

Your sleep study results come in the form of a detailed report that your doctor will review with you. The report includes measurements of your sleep stages, breathing patterns, and any disruptions that occurred during the night. Understanding these results helps your doctor determine if you have a sleep disorder and what treatment might be helpful.

One of the most important measurements is the Apnea-Hypopnea Index (AHI), which counts how many times per hour your breathing stops or becomes shallow. An AHI of less than 5 is considered normal, while 5-15 indicates mild sleep apnea, 15-30 is moderate, and over 30 is severe sleep apnea.

The report also shows how much time you spent in each sleep stage. Normal sleep includes light sleep, deep sleep, and REM (rapid eye movement) sleep. Your doctor will look at whether you're getting enough of each stage and if there are any unusual patterns or disruptions.

Other important measurements include your oxygen levels throughout the night, leg movements, and heart rhythm changes. Your doctor will explain what each finding means for your health and discuss treatment options if any problems are discovered.

How to improve your sleep quality after polysomnography?

If your sleep study shows normal results, you can focus on general sleep hygiene practices to maintain good sleep quality. Sometimes people have sleep complaints even when their overnight study appears normal. Your doctor might recommend keeping a sleep diary or trying different sleep habits to see what helps.

For those diagnosed with sleep apnea, CPAP (continuous positive airway pressure) therapy is often the most effective treatment. This involves wearing a mask connected to a machine that provides gentle air pressure to keep your airways open. While it takes some getting used to, most people feel dramatically better once they adapt to CPAP therapy.

Here are some general strategies that can improve sleep quality for most people:

• Stick to a consistent sleep schedule, even on weekends
• Create a relaxing bedtime routine
• Keep your bedroom cool, dark, and quiet
• Avoid screens for at least an hour before bedtime
• Limit caffeine and alcohol, especially in the evening
• Get regular exercise, but not too close to bedtime
• Consider relaxation techniques like deep breathing or meditation

Your doctor will work with you to develop a personalized treatment plan based on your specific results. This might include lifestyle changes, medical devices, medications, or referrals to specialists who can provide additional support.

What are the risk factors for needing polysomnography?

Certain factors make you more likely to develop sleep disorders that require evaluation with a sleep study. Age is one significant factor, as sleep apnea becomes more common as we get older. Being overweight also increases your risk, as extra tissue around the neck can block airways during sleep.

Family history plays a role too. If your parents or siblings have sleep apnea or other sleep disorders, you may be at higher risk. Men are more likely to develop sleep apnea than women, though the risk for women increases after menopause.

Several medical conditions can increase your likelihood of needing a sleep study:

• High blood pressure that's difficult to control
• Heart disease or irregular heart rhythms
• Diabetes or prediabetes
• Stroke or history of stroke
• Enlarged tonsils or thick neck circumference
• Nasal congestion or breathing problems
• Use of sedatives or muscle relaxants

Lifestyle factors can also contribute to sleep problems. Smoking irritates the airways and can worsen sleep apnea. Alcohol relaxes throat muscles, which can lead to breathing problems during sleep. Shift work or irregular sleep schedules can disrupt your natural sleep patterns.

What are the possible complications of untreated sleep disorders?

Ignoring sleep disorders can have serious consequences for your health and daily life. Sleep apnea, in particular, puts strain on your cardiovascular system and can lead to high blood pressure, heart disease, and increased risk of stroke. The repeated drops in oxygen levels during sleep can damage your organs over time.

Untreated sleep disorders also affect your mental health and cognitive function. Poor sleep quality can lead to depression, anxiety, and difficulty concentrating. You might find it hard to remember things or make decisions during the day. This can impact your work performance and relationships.

Here are some potential complications of untreated sleep disorders:

• Increased risk of car accidents due to daytime sleepiness
• High blood pressure and heart problems
• Weight gain and difficulty losing weight
• Weakened immune system
• Mood changes and irritability
• Relationship problems due to snoring or sleep disruption
• Increased risk of diabetes

The good news is that most sleep disorders are highly treatable once properly diagnosed. Early treatment can prevent these complications and dramatically improve your quality of life. Many people are amazed at how much better they feel after addressing their sleep problems.

When should I see a doctor for sleep problems?

You should consider seeing a doctor if you consistently feel tired during the day despite getting what seems like adequate sleep. If you find yourself falling asleep during quiet activities like reading or watching TV, this could indicate a sleep disorder. Loud snoring, especially if accompanied by gasping or choking sounds, is another important warning sign.

Pay attention to what your sleep partner tells you about your nighttime behavior. If they notice you stop breathing, make unusual movements, or seem restless throughout the night, these observations can provide valuable clues about potential sleep disorders.

Here are specific symptoms that warrant medical evaluation:

• Excessive daytime sleepiness that interferes with daily activities
• Loud snoring with periods of silence followed by gasping
• Witnessed episodes of stopped breathing during sleep
• Frequent nighttime awakenings
• Morning headaches or dry mouth
• Difficulty concentrating or memory problems
• Unusual behaviors during sleep like sleepwalking or talking

Don't wait if you're experiencing these symptoms regularly. Sleep disorders can significantly impact your health and quality of life, but they're also very treatable. Your primary care doctor can evaluate your symptoms and refer you to a sleep specialist if needed.