Our sleep needs change during our lifetime and varies by individual; but the most important factor is getting enough quality sleep. The American Sleep Apnea Association (ASAA) says people should feel alert and refreshed when they wake up, and not rely on napping to get through the day.
Scientists have determined that most adults need between seven and eight hours of sleep a night for optimal health. When you suffer from interrupted sleep, such as that caused by obstructive sleep apnea (OSA), you are more prone to a host of health problems ranging from heart disease to diabetes, and from cognitive decline to memory impairment. In children, lack of sleep can cause hyperactivity, according to the ASAA.
What are Sleep Cycles?
Sleep is broadly divided into stages that cycle throughout the night: wakefulness, rapid-eye movement (REM) sleep, and non-REM sleep. There are three stages of non-REM sleep, known as N1, N2 and N3, and one REM phase. Healthy sleepers cycle through these stages several times through the night. Let’s explore them in depth:
- Stage N1, the first non-REM stage, marks the transition from wakefulness to falling asleep. You may dream during this stage, be easily awakened, and aware of your surroundings to some degree.
- Stage N2 is the point at which your breathing becomes automatic and your heart rate slows down. Healthy adults spend about half their sleep time in this cycle.
- Stage N3 is also known as slow wave sleep or delta sleep because of the slower delta brainwaves recorded at this time. It is a regenerative stage in which the body repairs itself. The first N3 sleep stage of the night lasts between 45 and 90 minutes; thereafter it becomes progressively shorter. As people age, this stage gradually disappears.
- REM sleep episodes become longer through the night, occurring every 90 minutes or so. The rapid eye movement phase is marked by brain activity: the eyes dart about below the lids and you experience your most vivid and memorable dreams. The body remains in a quasi-paralyzed state, so you do not act out your dreams.
During a sleep study, your sleep cycles are recorded and analyzed. This is a valuable diagnostic tool. People with sleep apnea tend to stay in the N1 and N2 stages of light sleep, with interrupted episodes of the more restorative N3 and REM sleep. That is yet another reason sleep apnea can cause long-term physical harm, and why OSA demands prompt treatment.
If you would like to discuss your sleep quality, or suspect you have sleep apnea, contact our 21061 sleep medicine office and schedule an appointment.