The Valsalva maneuver is a breathing technique where you forcefully exhale against a closed mouth and nose, creating a sharp increase in pressure inside your chest and abdomen. You’ve probably done it without knowing the name: straining during a bowel movement, popping your ears on an airplane, or bracing your core during a heavy lift. In medicine, it’s used both as a diagnostic tool and a treatment, particularly for certain types of rapid heart rhythms.
How to Perform It
The technique is simple. Sit down or lie on your back. Take a deep breath in, then bear down as if you’re trying to have a bowel movement, keeping your mouth closed and pinching your nose shut. Hold that strain for 15 to 20 seconds, then release and breathe normally. The sensation is similar to the pressure you feel when pushing hard or blowing up a stiff balloon. In a clinical setting, doctors use a tube connected to a pressure gauge and aim for a target of 40 mmHg of sustained pressure for 15 seconds.
There’s also a reverse version. Instead of exhaling against resistance, you inhale against a closed nose and mouth for about 10 seconds while sitting upright. This creates negative pressure in the chest rather than positive pressure, and it’s used in different diagnostic contexts.
What Happens Inside Your Body
When you strain against a closed airway, the pressure inside your chest cavity spikes. That pressure squeezes the large blood vessels near your heart, temporarily reducing the amount of blood returning to it. Your blood pressure drops briefly, and your heart rate increases to compensate. Once you release the strain, blood rushes back in, blood pressure overshoots above its baseline, and your heart rate reflexively slows down.
This sequence also raises pressure inside your skull. In one study of patients with elevated intracranial pressure, the Valsalva maneuver caused an average spike of about 29 mmHg, though it returned to baseline within 16 seconds of starting the maneuver. The pressure changes were temporary and didn’t produce any lasting elevation. Intra-abdominal pressure rises too, which is the mechanism behind its use in weightlifting and why it can aggravate hernias.
Stopping a Racing Heart
The most well-known medical use of the Valsalva maneuver is treating supraventricular tachycardia (SVT), a type of abnormally fast heart rhythm that originates above the heart’s lower chambers. The maneuver works because the pressure changes in your chest stimulate the vagus nerve, a long nerve running from your brainstem to your abdomen that acts as a brake on heart rate. When activated, the vagus nerve slows electrical conduction through a critical relay point in the heart, which can break the loop sustaining the rapid rhythm.
In practice, the standard technique works only about 5 to 20% of the time, which is why emergency departments often move quickly to medications. But a modified version dramatically improves those odds. In a landmark trial published in The Lancet (the REVERT trial), researchers tested a simple tweak: after straining for 15 seconds in a semi-reclined position, the patient was immediately laid flat and had their legs raised to a 45-degree angle for 15 seconds. This leg elevation pushes more blood back toward the heart right at the moment vagal stimulation is strongest. The modified technique restored normal rhythm in 43% of patients, compared to 17% with the standard Valsalva alone.
Research on the underlying mechanism shows that success depends on two factors: how strongly a person’s vagus nerve responds and the specific electrical properties of their heart’s conduction pathways. In a study of 133 patients with different types of SVT, vagal maneuvers terminated the arrhythmia in 53% of those with one common subtype. The takeaway is that the maneuver doesn’t work for everyone, but it’s worth trying because it’s noninvasive and can spare you a trip to more aggressive treatments.
Equalizing Ear Pressure
Scuba divers and airline passengers use the Valsalva maneuver constantly, often without knowing its name. When you descend underwater or when a plane drops altitude, the air pressure outside your eardrum increases faster than the pressure behind it. This creates a painful inward push on the eardrum. By performing the maneuver (pinching your nose, closing your mouth, and gently blowing), you force air up through the eustachian tubes, the narrow passages connecting your throat to your middle ear. When the pressure equalizes, you feel that familiar “pop” and the discomfort resolves.
This works best when done early and often during descent, before the pressure difference becomes large enough to lock the eustachian tubes shut. Divers are taught to equalize every few feet rather than waiting until they feel pain. If the tubes are already swollen from a cold or allergies, the maneuver may not work at all, which is why diving or flying with significant congestion can lead to ear injuries.
Spine Stability During Heavy Lifting
Powerlifters and strength athletes deliberately use the Valsalva maneuver before heavy squats, deadlifts, and presses. Taking a deep breath and bracing against a closed airway raises intra-abdominal pressure, which acts like an internal weightlifting belt. Research confirms that the maneuver alone increases intra-abdominal pressure, and combining it with resistance exercise raises that pressure even further. The result is greater rigidity through the trunk and more stability for the spine under heavy loads.
This is effective for short, maximal efforts, but it comes with a tradeoff. The spike in blood pressure during the strain phase is significant, and repeatedly performing heavy Valsalva efforts can cause lightheadedness or, in rare cases, fainting when the strain is released and blood pressure temporarily drops. People with cardiovascular conditions or uncontrolled high blood pressure should be cautious with this technique. For most healthy lifters performing brief, controlled repetitions, the stabilizing benefit outweighs the transient pressure spike.
Diagnostic Uses
Doctors use the Valsalva maneuver as a bedside diagnostic tool in two main ways. First, it helps differentiate heart murmurs. Because the maneuver reduces the volume of blood inside the heart, it changes how murmurs sound through a stethoscope. Most murmurs get quieter when less blood flows through the heart. But the murmur of hypertrophic cardiomyopathy (a condition where the heart muscle is abnormally thick) actually gets louder, because the smaller blood volume allows the thickened muscle to obstruct the outflow path more. Mitral valve prolapse also becomes more audible. This contrast helps doctors narrow down a diagnosis without imaging.
Second, the maneuver tests the health of the autonomic nervous system, the part of your nervous system that controls involuntary functions like heart rate and blood pressure. By monitoring how your heart rate and blood pressure respond through all phases of the strain and release, doctors can detect problems with conditions like diabetic neuropathy, heart failure, and other disorders that impair the body’s automatic cardiovascular regulation. An abnormal response pattern, where blood pressure drops but heart rate fails to compensate, points to autonomic dysfunction.
Risks and Situations to Avoid
For most people, the Valsalva maneuver is safe when performed briefly. The risks come from the pressure spikes it generates. The sharp rise in intracranial pressure makes it a concern for anyone who has had recent eye surgery (particularly procedures affecting the retina or lens), because the pressure can transmit to the eye. People with known brain aneurysms or recent stroke should avoid it for the same reason.
The maneuver can worsen or reveal a hernia, since the abdominal pressure increase pushes tissue into weak points in the abdominal wall. In fact, doctors sometimes ask patients to perform the maneuver specifically to make a hernia more visible during examination. If you have an existing hernia, repeated forceful straining can make it worse. People with severe uncontrolled hypertension, unstable heart conditions, or significant aortic valve disease should also avoid it, as the rapid blood pressure swings can be dangerous in those contexts.