Why do I feel dizzy after breathing exercises?
On this page
Usually because you breathed more air than your body needed, or held your breath too long. Big breaths blow off carbon dioxide, and low carbon dioxide narrows the blood vessels to your brain. Sit down, breathe normally, and next time keep the slow pace but make each breath smaller.
People expect a breathing exercise to bring in more oxygen, so a head rush feels like the oxygen arriving. Your blood is already close to full of oxygen when you’re sitting still, at 95 to 100 percent for most people. What changes when you breathe big is carbon dioxide going down, and that’s what makes your head swim.
What we’d do
Sit or lie down for every session, so a head rush can’t make you fall. If you get dizzy, stop the pattern and breathe normally until it clears. Next time, keep the same slow count and breathe more quietly, as if you didn’t want anyone to hear. If holds are in the pattern, make them shorter.
Why your head swims
When you breathe more than you need, carbon dioxide in your blood falls. The Cleveland Clinic explains that this narrows your blood vessels, including the ones that bring blood to your brain, and lists “feeling lightheaded, dizzy or weak” among the symptoms. The Merck Manual adds that it can make some people faint.
It’s the same dizzy feeling you get from blowing up a pile of balloons for a party. Your oxygen is fine. You’ve breathed out a lot of carbon dioxide in a short time.
Slow patterns can do it too
Slow doesn’t always mean small. In a 2025 lab study, 84 students tried square breathing, 4-7-8 and six breaths a minute. Six a minute led to mild over-breathing, with their carbon dioxide falling a little, even though it’s one of the gentlest patterns there is. With a long count it’s easy to fill your lungs all the way every time, and those big breaths add up.
Dr. Andrew Weil’s handout for 4-7-8 says not to worry about feeling a little lightheaded at first, since it will pass. If it doesn’t pass within a few breaths of normal breathing, the pattern is too big for you right now.
Holds and fast rounds
Holding your breath after fast breathing is a different kind of dizzy. Your carbon dioxide is low, so you don’t feel the urge to breathe, while your oxygen keeps falling. That’s how people black out without warning, and it’s why fast rounds and long holds belong on a bed or the floor, never in water or in the car. More in is holding your breath bad for you.
When it’s not the exercise
If you feel dizzy or breathe fast when you haven’t been doing any exercise, and it’s the first time, MedlinePlus and the Cleveland Clinic both say to get medical help right away. The same goes if you faint, or the dizziness comes with chest pain.
7 sources
- Cleveland Clinic, Hyperventilationmy.clevelandclinic.org
- Merck Manual Professional Version, Respiratory alkalosismerckmanuals.com
- Marchant J et al., Comparing the effects of square, 4-7-8, and 6 breaths-per-minute breathing conditions on heart rate variability, CO2 levels, and mood, Applied Psychophysiology and Biofeedback, 2025pubmed.ncbi.nlm.nih.gov
- Andrew Weil, 4-7-8 Breath, Andrew Weil Center for Integrative Medicine, University of Arizonaawcim.arizona.edu
- Cleveland Clinic, Blood oxygen levelmy.clevelandclinic.org
- Boyd C et al., Notes from the field: hazardous breath-holding behaviors, New York, 1988 to 2011, MMWR, 2015cdc.gov
- MedlinePlus, Hyperventilationmedlineplus.gov
