Alpha Waves and Your Sleep

Alpha waves are a type of brain wave that's active while you're resting, especially when your eyes are closed. They're most common right before you drift off to sleep.

When alpha waves are measured, such as by a sleep doctor, the measurement is generally taken from the occipital region of the brain, which is in the back of your head. They're recognized by their rhythm, which is between 8 and 13 cycles per second, or hertz (Hz).

Man sleeping in bed
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Non-Sleep-Related Alpha Activity

Alpha wave activity isn't always related to sleep. It just means your brain is in a relaxed state, but you're still awake.

In addition to just before sleep, alpha waves can be present when you're:

  • Daydreaming
  • Practicing mindfulness
  • Meditating
  • During aerobic exercise

"Good" vs "Bad" Alpha Activity

Increasing alpha activity is a good thing. It offers several benefits, according to research. It has been found to:

  • Boost creativity
  • Reduce symptoms of depression
  • Manage chronic pain

Sometimes alpha waves occur when they're not wanted. Your brain shouldn't produce alpha waves while you're asleep, and when it does, the inappropriate alpha activity can lead to sleep disorders.

How Alpha Activity Is Measured

The most common test for measuring brain waves, including alpha waves and alpha activity, is an electroencephalogram (EEG). An EEG is what is used during an overnight sleep study, such as those done to diagnose sleep disorders such as obstructive sleep apnea (OSA).

To perform this test, a doctor or technician places small metal electrodes on your scalp and attaches them to a machine that can measure the brain patterns transmitted by the electrodes.

After the test is over, the patterns are read by a neurologist, who can use the information to diagnose various conditions, including sleep disorders and the risk of seizures.

When Alpha Activity Is Disrupted

When your alpha activity is disrupted, it can make you unable to relax and reduce the quality of your sleep. That can leave you tired and low on energy the next day. If the disruption is chronic, the fatigue can be as well.

One example of chronic alpha activity disruption is something called the alpha-EEG anomaly, which is an abnormal sleep pattern that occurs most often in people with the chronic pain condition fibromyalgia.

During deep sleep, the brain should be producing delta waves. In people who experience the alpha-EEG anomaly, the brain mistakenly produces alpha waves during these periods instead. This can lead to restlessness and sleep that is not refreshing.

Other Types of Brain Waves

Brain waves are behind everything you think, feel, perceive, and do. They're generated by the synchronized electrical pulses that masses of brain cells use to communicate with each other.

Your brain waves change throughout the day, depending on what you're doing. Slower waves are associated with the relaxed brain, while faster waves mean your brain is performing complex tasks.

Just as alpha waves do, every type of brain wave has its time and place. Other types of brainwaves include:

  • Delta waves: At .5 to 3 Hz, delta waves are the slowest of the brain waves. They occur when you're in the deepest states of sleep. 
  • Theta waves: At 3 to 8 Hz, theta waves also occur during sleep. In addition, they've been observed in very deep states of meditation.
  • Beta waves: These are the most common daytime brain waves, with a rhythm of 12 to 30 Hz. Beta waves are dominant in normal wakeful states, such as when you're focused on cognitive tasks, problem-solving, decision making, or similar activities.
  • Gamma waves: With a rhythm of 25 to 100 Hz, gamma waves are the fastest of the brain waves. They process information from various areas of your brain and are responsible for your conscious perception.
10 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Brandon Peters, MD
Brandon Peters, MD, is a board-certified neurologist and sleep medicine specialist.