삼성서울병원

If you feel tired even though you get plenty of sleep, something is wrong!
People say things such as, "I heard that we normally need seven hours of sleep if we want to be healthy," or "Last night, I only slept for three hours.

When we talk about sleep, we usually tend to put our focus on the length of sleep. However, the quality of sleep also matters. Even if you sleep long enough and feel sluggish and tired, that means your “sleep efficiency” is poor. If so, you need to find the causes and treat them to improve your performance in your daily life.

Today, we will learn about the two major causes of sleep quality deterioration:sleep apnea and restless legs syndrome.

If you snore heavily, that means there are difficulties in breathing during sleep. Snoring occurs when we forcefully respire through the narrowed airway while sleeping. In South Korea, about 10 to 30 percent of adults snore, and almost half of them are patients with sleep apnea, which can cause myocardial infarction, stroke, and even death.

Sleep apnea refers to the state of not breathing during sleep. It can be observed that the patient pants for a while then snores when reaching a certain point. If the number of instances of not breathing for more than ten seconds during an hour is over seven, it can be said to be serious sleep apnea. If sleep apnea persists, people have difficulties in their daily lives because of chronic fatigue and drowsiness caused by an insufficient oxygen supply. Secondly, it is highly likely to develop into cardiovascular disease or stroke. As a result, you need to be aware of the risks of sudden death caused by sleep apnea and treat it fundamentally.

Restless legs syndrome is a sleep disorder that is caused by leg movements due to intense, uncomfortable sensations in the legs, mainly before falling asleep. There are various symptoms such as the sensations of a worm moving on the legs, electricity flowing, restlessness, cramping, being pulled, or being burned. In some cases, patients may have difficulty in keeping their legs still, even when they are awake. The features of the syndrome are that the uncomfortable feelings occur more often at night than in the daytime, and it becomes worse when the legs are still, returning to normal when they are moving again.

Although the primary cause has not yet been identified, it is considered that the activity of dopamine, a hormone in the brain, abnormally decreases during the night and is restored again in the morning. In addition, it can occur due to iron deficiency anemia, diabetic polyneuropathy, or pregnancy. In rare cases, it can happen when there is a deficiency in minerals or vitamins. The syndrome may appear when muscle fatigue is increased because of excessive exercise during the day, excessive intake of caffeinated beverages, or prolonged exposure to high or low temperatures.