Why Do I Get Dizzy After Swimming?

When navigating a swim course, heading to T1, or climbing out of the pool after a workout, some athletes might get lightheaded. It’s a disconcerting and disruptive feeling to get dizzy after swimming, and some athletes may even wonder if it’s a sign of something more serious.

“There are many reasons a triathlete might experience dizziness while swimming or after getting out of the water,” said Dr. Leah Roberts of SteadyMD. “Though some are caused by issues with the vestibular system (the inner-ear system that senses and maintains equilibrium and balance), there are other issues that may be at play, such as blood pressure regulation, nutrition issues, or even panicking.”

To get rid of the spins after time in the pool, it’s important to pinpoint the underlying cause. Here’s how to troubleshoot dizziness after swimming, plus signs that it may be time to check in with your primary healthcare provider.

Why do I get dizzy after swimming?

Nutrition issues

Are you starting your swim on an empty stomach? If you’re swimming in a fasted state – whether by deliberate choice before a workout or as a byproduct of race-morning nerves – you might feel lightheaded during or after the swim. 

As the first discipline of triathlon, nutrition issues are less likely to manifest in the swim than on the bike or run, but they can and do happen. Race morning nerves can easily lead to stomach upset, causing an inability to top off carbohydrate and fluid stores. Because it’s hard to fuel while in the water, blood sugar drops over long swims, like those in an Ironman, may cause dizziness.

Swims that are warm, but still wetsuit-legal, can also be particularly problematic by causing higher-than-expected levels of fluid loss and dehydration. This is especially true for athletes with higher sweat rates. According to Roberts, the resulting loss of plasma volume in these scenarios can contribute to a blood pressure drop, which can make some people dizzy.

Cold water

Cold water swimming can affect us in all sorts of ways – feeling fatigued, a sensation of pins-and-needles, and, in some cases, dizziness. According to doctor of audiology and triathlete Carolynne Pouliot, when cold water makes direct contact with the eardrum, the density of a fluid called endolymph in the semicircular canal (part of the inner ear) changes. This sends faulty signals to the brain that cause sensations of head turning and vertigo.

Additionally, cold water causes a constriction of blood vessels (vasoconstriction), which reverses into a widening of the blood vessels (vasodilation) as the body warms upon exiting the water. This contributes to orthostatic hypotension (below) and dizziness. The water you swim in doesn’t have to be freezing for this phenomenon to occur. “Even milder water temperatures (75-80 degrees F) can induce vasoconstriction (as) blood vessels in our extremities constrict to shunt more blood flow to the core,” said Roberts.

Tight wetsuit

Wrestling into a too-tight wetsuit is difficult for anyone, and the resulting constriction can have effects that go beyond decreased shoulder mobility and a sense of discomfort. Along with sensations of being choked, an overly tight wetsuit neck can also put pressure on some key structures running through the neck – namely, the vagus nerve and the arteries that supply blood to the brain. The vagus nerve plays a role in slowing heart rate, decreasing blood pressure, and decreasing blood vessel tone, and compressing that nerve can result in feelings of dizziness and potential syncope (passing out). The full-body compression of an overly restrictive wetsuit can also lead to feelings of shortness of breath and claustrophobia that contribute to disorientation and panic, which brings us to the next item on the list of possible causes of feeling dizzy during or after a swim:

Panicking

Race morning nerves, physical swim starts, the shock of cold water, the aforementioned wetsuit constriction, choppy water, poor visibility – let’s be real, a high-adrenaline race environment can induce anxiety and panic in even the most experienced triathletes. Lightheadedness and dizziness frequently accompany panic attacks. According to Roberts, the most common cause of this link is the rapid breathing of hyperventilation, which removes too much carbon dioxide from the body, upsets blood pH, and causes symptoms that include lightheadedness and dizziness. Additionally, stress hormones may have disruptive impacts on the vestibular system. If a person has underlying vestibular function, adding anxiety – about the race or about the dizziness itself – to the equation can further exacerbate symptoms.

Orthostatic hypotension

Orthostatic hypotension refers to a significant drop in blood pressure that occurs when moving from a laying down to an upright position; in this case, moving from a prone swimming position to an upright one upon exiting the water. When we stand up, gravity sends blood to the lower extremities. In response, the body increases heart rate, cardiac output, and venous return of blood to the heart while constricting blood vessels in order to combat blood pressure drops and prevent dizziness.

Swimming, however, has been postulated to decrease activity of the lower extremity muscle pumps that increase venous return, and endurance exercise in general can lead to nervous system changes that result in vasodilation, further decreasing blood pressure. In the water, hydrostatic pressure naturally assists venous return, so losing that mechanism upon exiting the water can cause feelings of lightheadedness, dizziness, and feeling like you’re about to pass out.

Orthostatic hypotension can be exacerbated by a lot of factors, including the nutritional and cold-water considerations above. Roberts also cautioned that some medications, especially certain types of blood pressure medications, leave athletes at higher risk for this condition.

Benign Paroxysmal Positional Vertigo (BPPV)

BPPV is a condition in which the inner ear is mechanically disrupted. According to Pouliot, BPPV occurs when the otoconia, small crystals in the inner ear that assist with balance, become dislodged, causing sensations of vertigo. This sensation of spinning is particularly strong with certain head movements, including quickly turning the neck to breathe or sight while swimming. While the cause of BPPV is often idiopathic (unknown), rapid, repetitive head turning with swimming has been postulated to contribute to the development or exacerbation of BPPV. Head trauma has also been indicated as a cause of BPPV, so theoretically, a kick to the head during a rough swim start could play a role. 

BPPV typically causes vertigo that is described as “room-spinning” and would persist once on solid ground with certain head movements, so it should be considered as a cause of dizziness when symptoms continue long after the swim has ended.

Other underlying inner ear issues/vestibular weakness

If you’re prone to motion sickness, particularly when reading, you might also be more likely to experience dizziness while swimming.

On land, the ability to maintain orientation in space and balance is a function of three inputs: the vestibular system, proprioceptive sensory information (information from the feet and lower extremity joints about where the body is in space), and vision. In water, proprioceptive information is distorted, and choppy conditions, cloudy water, or foggy goggles can make visual information hard to come by. This puts the onus on the vestibular system to make sense of where the body is in space, and can lead to disorientation and a sense of dizziness. This is particularly true for those who may have an underlying vestibular disorder or weakness.  

“Swimming would exacerbate any peripheral balance problem, since you’re taking out the brain’s additional information,” Pouliot said.

Cervicogenic dizziness

Cervicogenic dizziness refers to a sense of dizziness, disorientation, and imbalance that accompanies other neck issues. These sensations often occur in conjunction with neck pain and headaches related to certain movements and positions. Although its etiology is not fully understood, head or neck injuries, such as whiplash, may contribute to its development. In people with this condition, muscular tightness and trigger points are also frequently present. 

The head and neck movements, upper body exertion, and pre-start nerves are all factors that can increase neck muscle and joint strain, triggering episodes of cervicogenic dizziness. Cases in swimmers have been reported upon in medical literature, and physical therapists often attest that when patients with neck pain also present with dizziness, successful treatment of the pain often addresses the dizziness, as well.   

Bow Hunter’s Syndrome (Rotational Vertebral Artery Occlusion Syndrome)

This rare but potentially serious cause of dizziness with swimming occurs when structural abnormalities of the neck, such as bone spurs or disc herniations, cause mechanical occlusion of the vertebral arteries. This compression happens during neck rotation and/or extension – the very motions inherent to sighting and swimming. Underlying stenosis, or narrowing of the artery, may also be present. 

The resulting dizziness, vertigo, and headaches are signals that blood is not being delivered to the brain. Repeated compression of the artery can lead to internal damage, clot formation, and stroke, so symptoms of vertigo related to neck rotation or extension with swimming should be taken seriously.

How to get rid of dizziness when swimming

Roberts and Pouliot say small adjustments to the way you swim may help relieve symptoms of dizziness. Their recommendations:

1. Fuel properly. While nervous pre-race stomachs might not be up a full breakfast, topping off fuel and hydration stores before races and longer swim workouts and getting in fluids can help prevent both blood sugar and dehydration-related causes of dizziness. Volume depletion is also implicated in orthostatic hypotension, particularly in cold water swims, so proper hydration is important in all conditions.
2. Wake up the legs. To reduce orthostatic hypotension, increase your kicking as you make your way toward the swim exit. Using those legs will activate the muscle pumps that help promote the return of blood to the heart. 
3. Try earplugs. For athletes that find themselves prone to dizziness in cold water, earplugs to prevent water from reaching the eardrums may help. Roberts also recommends keeping the core temperature warm with proper swimwear (as allowed) in order to minimize vasoconstriction.
4. Get a wetsuit that fits well, and wear it before race day to become familiar with any feelings of constriction that may occur.
5. Learn to manage your nerves. In addition to practicing in open water before race day, athletes should develop an arsenal of calming techniques. Strategies like deep breathing, self-talk, and using a safety stroke can decrease the panic response that leads to swim dizziness.

Put all of these strategies into practice well before race day. Overall, experience is a great teacher. If these strategies fail, however, it may be time to check in with your primary care physician.

When to see a doctor

While some causes of dizziness with swimming can be minimized with the actions discussed above, others do require medical attention. If you’re experiencing persistent or intense, room-spinning vertigo accompanied by nausea or vomiting, there’s a good chance the cause of your swimming dizziness is linked to a medical issue.

Some causes, such as BPPV, can be readily addressed through simple maneuvers performed by practitioners with vestibular training, while others, such as cervicogenic dizziness, often respond to muscle and joint manual therapies and targeted exercises. Just like with a muscle, an underlying weaker vestibular system can also be strengthened with specific exercises prescribed by a vestibular specialist physical therapist. 

While a one-time episode of orthostatic hypotension after a swim may not be cause for concern, especially if other causes (dehydration, cold water) can be identified, repeated, consistent episodes should be evaluated to rule out underlying cardiac deficiencies, and athletes on blood pressure medications should discuss swimming with their physicians.

Bow hunter’s syndrome can lead to serious complications, including vertebral artery damage, blood clots, and stroke, so vertigo that reproducibly occurs at certain degrees (usually greater than 30) of neck rotation and extension should be promptly investigated. Finally, any symptoms of dizziness and vertigo that are persistent with daily life and cannot be readily attributed to other causes do deserve medical attention.