The Valsalva maneuver—forcefully exhaling against a closed airway—triggers a cascade of measurable changes throughout the cardiovascular system, from shifting blood pressure to temporarily altering heart rate. First described in the 1700s as a technique to clear the ears, it’s since become both something people do unconsciously every day and a deliberate clinical tool used to diagnose heart conditions and treat certain arrhythmias.
What the Maneuver Actually Involves
The Valsalva maneuver is a particular way of breathing that increases pressure in the chest, causing various effects in the body including changes in heart rate and blood pressure. To perform it, you inhale deeply, hold your breath, tighten your chest and stomach muscles, and bear down as if straining to have a bowel movement, holding that position for about 10 seconds before breathing out forcibly. Many people perform a version of this maneuver without realizing it—for example, when pushing during a bowel movement. Similar pressure changes occur when someone strains during a heavy lift while holding their breath, or during a forceful cough.
The Four Phases of Cardiovascular Response
Researchers divide the body’s response into four distinct phases, each with its own blood pressure pattern.
Phase one kicks off as soon as you begin straining. Blood pressure temporarily rises as some blood is pushed into the aorta, the major artery that carries oxygen-rich blood through the body.
Phase two follows as the strain continues. As intrathoracic pressure builds and pressure in the chest reduces venous return, blood pressure falls, and the baroreceptor—a sensor in the carotid artery—detects this change, causing blood vessels to narrow and the heart rate to speed up as a compensatory response. This happens because increased intrathoracic pressure and decreased venous return trigger reduced parasympathetic activity and increased sympathetic nervous system activity.
Phase three happens the moment you release the strain. Pressure releases suddenly, causing a further dip in blood pressure. Aortic pressure briefly decreases as the external compression on the aorta is removed, and heart rate briefly increases again reflexively.
Phase four brings the system back toward baseline—and briefly past it. Typical blood flow to the heart resumes, causing blood pressure to increase and overshoot its baseline level, which leads to a slower heart rate as the body settles back to normal. This overshoot happens because cardiac output suddenly increases in response to a rapid rise in cardiac filling, combined with a baroreceptor-mediated increase in blood vessel resistance that built up during the strain.
Effects on Heart Function and Blood Flow
The maneuver’s core mechanism centers on how it interferes with normal heart filling. The maneuver produces significant hemodynamic changes, primarily an increase in intrathoracic pressure that reduces preload—the volume of blood returning to the heart before it contracts. This chain of events was first documented in detail in 1950, when researcher Edward Peter Sharpey-Schafer described a rise in intrathoracic pressure, a decrease in heart-filling pressures, and a decreased stroke volume during the maneuver. Notably, the left and right sides of the heart don’t respond identically—research using beat-by-beat measurement found that the left and right heart have different physiological responses to the Valsalva maneuver, reflecting how differently pressure changes propagate through each side of the circulatory system.
Overall, the maneuver reduces cardiac output, the amount of blood the heart pumps out with each beat—which is precisely why it can cause lightheadedness or, in rare cases, more serious effects. In an extreme early account, one researcher performing the maneuver on himself experienced bradycardia (an abnormally slow heart rate) and lost consciousness.
Effects Beyond the Heart
The pressure changes triggered by the maneuver ripple out to organs well beyond the cardiovascular system.
Eyes. The Valsalva maneuver has been reported to cause elevated intraocular pressure, which is part of why straining is often discouraged for people with certain eye conditions.
Abdominal organs. During the maneuver, intra-abdominal pressure increases while mean arterial pressure drops slightly below baseline, decreasing abdominal tissue perfusion pressure and reducing hepatic venous blood flow. Interestingly, this pressure shift appears to physically soften abdominal organs. Research using elastography found that the Valsalva maneuver decreases measured stiffness in both the liver and the spleen.
Brain blood vessels. The maneuver can induce changes in hemodynamic function that affect cerebral vascular functionality, including arterial elasticity, with research showing measurable shifts in carotid artery diameter and pulse wave velocity following the maneuver.
Clinical and Everyday Uses
Because the maneuver’s effects on heart rate and blood pressure are so predictable, doctors use it deliberately for both diagnosis and treatment. Originally developed to expel fluids and foreign bodies from the middle ear, it has since evolved into a critical clinical tool across cardiology and neurology. A related variation offers a treatment option for certain fast heart rhythms. The reverse Valsalva maneuver, performed while sitting and inhaling against resistance for 10 seconds with the nose pinched, increases vagal tone and decreases sympathetic activity, leading to a slowed heart rate and drop in blood pressure—and if effective, can resolve supraventricular tachycardia within about 15 seconds.
A Caution Around Repeated or Excessive Use
While an occasional Valsalva maneuver is generally harmless for healthy individuals, repeated or excessive use carries some risk. In the short term, the maneuver can cause a temporary increase in blood pressure, but over time, excessive use can lead to increased blood pressure and other health issues, which is one reason fitness professionals are trained to instruct clients on proper technique to minimize adverse effects during heavy lifting.
Join The Discussion
Have you used the Valsalva maneuver intentionally—whether to pop your ears, manage a fast heart rate, or as part of a lifting routine—and did you notice the phases of blood pressure change described here? Do you have questions about when this technique is safe to use versus when it’s better avoided? Share your experiences, questions, or anything else you’ve learned about this maneuver below.
